Starting Electrical Issues
02-03-2017, 01:47 AM
#1
Starting Electrical Issues
*Sorry about the long post*
**Scroll down for short version**
I have been having trouble locating what I believe is an electrical problem in the starting circuit of my 2008 F150. I have attached a picture of the circuit along with a diagram of the fuse box. I will explain what has happened already.
The problem started in December when I got stranded at South Mountain. I tried getting a jump but that didn't work. I got a ride to Autozone and replaced my battery because it was a few years old anyway. Still couldn't get it to work so I called a tow truck. While I was waiting, I put the truck in neutral, started coasting down the hill and the truck started! My truck is an automatic and I'm not sure why this worked. I cancelled the tow, went home, came back a few hours later and the truck started. I drove to Autozone to have them test my starter. He hooked up the device, I turned my truck off, and then it wouldn't turn back on. The employee said my starter failed so I replaced that. My truck started up at least 5 times with the new starter but one time it didn't start (stranded at Fry's). I realized this didn't fix the problem but I had purchased a reman starter and thought maybe it was bad. I swapped it for a brand new Duralast but that didn't fix the problem.
-At this point I have a brand new battery ($139.89) & starter ($179.50).
Occasionally when the truck wouldn't work, I would rock it while in park and that allowed me to start the truck. I thought of this because of the coasting down a hill in neutral that worked for me previously. Since this seemed to fix the problem I was told to look into the neutral safety switch. Since it was relatively cheap I decided to buy one from Autozone and swap it out myself. The truck started but I eventually ended up getting stranded again.
-At this point I have a brand new battery, starter, and digital range transmission sensor (NSS). Plus I am getting frustrated
.
I did learn during that time that the rocking of the truck didn't always work. One time I rocked the **** out of the truck while my sister tried starting it and it wouldn't start. I let the truck cool down for a few hours and it would start. I started thinking the wires, relay, or ignition switch was creating a problem when hot. I tried looking into a few things over the next couple weeks. I tested the starter relay and ignition switch and both seemed fine. One time I tried swapping the starter relay with my hibeam headlight relay and got half a crank. This led me to believe there wasn't a good contact in there. I swapped the relay back and got the truck to start while I was cranking and wiggling the relay.
One night the truck wouldn't start so I tried messing with it. I saw in a video a guy used a wire to bridge terminals 30 and 87 I believe to get the truck to start with bypassing the ignition switch. I tried this but got a spark and I think I messed something up by doing this. I also tried wiggling the wiring harness coming off the battery that night but ever since then the truck won't start. I think I did something with those terminals but I'm new to the electrical aspect of this. Is it possible I blew a fuse or shorted something by doing this? I'm not sure how to check the big square fuses in my truck. I've seen posts that say they are stubborn to get out and others say they are screwed on. Either way I haven't been able to check any of those fuses.
I decided to order new battery cables from Amazon because my friend believed that we broke a wire while wiggling the wiring harness. I also wasn't getting any voltage on the ignition post of the starter solenoid. I ordered the complete set-up from Amazon that replaced the positive and negative battery cables, along with the few grounds coming off it and the 3 cables going to the starter. I also helped my sister out with her truck. I helped replace her lower control arms, sway bar links, and a few other things related to steering and suspension. She ended up buying me a new ignition switch to compensate me for my time and labor.
- At this point I have a brand new battery, battery cables, starter, NSS and ignition switch. I've spent $437.54 + $52.30 for the ignition switch my sister bought me. This has replaced just about every part in my starting circuit and many of the parts have lifetime warranties which is the only silver lining I can see about this right now. The starter, NSS and ignition switch all have limited lifetime warranties and the battery is 3 year and then a pro-rate for the next 2 years after that. Plus I have the original parts that I replaced for backups just in case. Needless to say, I know at this point I went about this the wrong way. I've learned a lot and if I knew then what I know now, I could've avoided buying all these parts.
Alright so here is the point where I'm at. I can't start the truck EVER. The only way I can start it at this point is to bypass the ignition switch, NSS, relay, etc. I use my jumper cables to pass current from the positive battery terminal to the ignition post on the starter solenoid. As long as the key is in the run position, I can start my truck and get around. This is annoying but at least I now know how to start the truck no matter what. None of this guessing like I did before with rocking the truck and letting it cool off. From this I've learned that the signal is not being sent. I've checked the tan/red wire that comes from the NSS to the relay box. When the truck was starting and I would see ~12V there. Last time I checked without the truck turning on and I saw voltage but I don't think there was at least 12V. I'm not sure if I wasn't making a good contact or what. I also know that the ignition post on the solenoid is not getting power. Tracing this back a bit I had replaced part of the yellow/blue wire but not all of it. The battery cables have an area where this wire clips in. This yellow/blue wire I believe then goes into the wiring harness and to the back of the fuse box/ relay. I also checked the red/blue wire coming out of the ignition switch and I was getting ~12V when the truck would start (cranking) but when I turn the key to start and it won't start, I'm not getting 12V coming out of there. I just checked and I don't think I'm getting power to the ignition switch anymore. I don't think the green/purple wire has any voltage anymore. It's dark and I'm using a flashlight so it's possible the tip wasn't making contact but is it possible I blew that 20A fuse (F102)? It's one of those square fuses that I'm not sure how to check.
**SHORT VERSION**
New battery, battery cables, starter, neutral safety switch and ignition switch. Can anyone walk me through the steps I need to locate the problem? I have the wiring diagram uploaded and I think I understand it pretty well it's just that I'm new to this so not sure what to do. I know the red wire going from the battery to starter is good. I'm assuming the black/orange wire going to the charging circuit is good because my truck runs fine after I start it, I just can't get it started using the starting circuit. Only way to start my truck is put the key to run and apply 12V to the ignition post on starter solenoid. Can someone help walk me through the middle path of the diagram? I tried locating the yellow/green wire the goes from the battery to F102 but I haven't been able to find it yet. I think it might run behind the battery but I'm not sure. I just checked the green/purple wire going to the ignition switch and I don't think I have voltage anymore. I used to have constant voltage there and now I believe it's 0V. Could I have blown F102? I checked the red/blue wire and I don't have voltage either (when cranking). I used to get voltage when the truck started but the truck won't start anymore. I'm assuming this is part of the problem. I've tried adjusting the NSS also but I think it's good. I know that power is not getting to the relay because I don't hear the click. I'm also not getting 12V from the tan/red wire or the yellow/blue wire. Thanks in advance for any help.
http://www.autogenius.info/ford-f-15...e-box-diagram/
**Scroll down for short version**
I have been having trouble locating what I believe is an electrical problem in the starting circuit of my 2008 F150. I have attached a picture of the circuit along with a diagram of the fuse box. I will explain what has happened already.
The problem started in December when I got stranded at South Mountain. I tried getting a jump but that didn't work. I got a ride to Autozone and replaced my battery because it was a few years old anyway. Still couldn't get it to work so I called a tow truck. While I was waiting, I put the truck in neutral, started coasting down the hill and the truck started! My truck is an automatic and I'm not sure why this worked. I cancelled the tow, went home, came back a few hours later and the truck started. I drove to Autozone to have them test my starter. He hooked up the device, I turned my truck off, and then it wouldn't turn back on. The employee said my starter failed so I replaced that. My truck started up at least 5 times with the new starter but one time it didn't start (stranded at Fry's). I realized this didn't fix the problem but I had purchased a reman starter and thought maybe it was bad. I swapped it for a brand new Duralast but that didn't fix the problem.
-At this point I have a brand new battery ($139.89) & starter ($179.50).
Occasionally when the truck wouldn't work, I would rock it while in park and that allowed me to start the truck. I thought of this because of the coasting down a hill in neutral that worked for me previously. Since this seemed to fix the problem I was told to look into the neutral safety switch. Since it was relatively cheap I decided to buy one from Autozone and swap it out myself. The truck started but I eventually ended up getting stranded again.
-At this point I have a brand new battery, starter, and digital range transmission sensor (NSS). Plus I am getting frustrated
.I did learn during that time that the rocking of the truck didn't always work. One time I rocked the **** out of the truck while my sister tried starting it and it wouldn't start. I let the truck cool down for a few hours and it would start. I started thinking the wires, relay, or ignition switch was creating a problem when hot. I tried looking into a few things over the next couple weeks. I tested the starter relay and ignition switch and both seemed fine. One time I tried swapping the starter relay with my hibeam headlight relay and got half a crank. This led me to believe there wasn't a good contact in there. I swapped the relay back and got the truck to start while I was cranking and wiggling the relay.
One night the truck wouldn't start so I tried messing with it. I saw in a video a guy used a wire to bridge terminals 30 and 87 I believe to get the truck to start with bypassing the ignition switch. I tried this but got a spark and I think I messed something up by doing this. I also tried wiggling the wiring harness coming off the battery that night but ever since then the truck won't start. I think I did something with those terminals but I'm new to the electrical aspect of this. Is it possible I blew a fuse or shorted something by doing this? I'm not sure how to check the big square fuses in my truck. I've seen posts that say they are stubborn to get out and others say they are screwed on. Either way I haven't been able to check any of those fuses.
I decided to order new battery cables from Amazon because my friend believed that we broke a wire while wiggling the wiring harness. I also wasn't getting any voltage on the ignition post of the starter solenoid. I ordered the complete set-up from Amazon that replaced the positive and negative battery cables, along with the few grounds coming off it and the 3 cables going to the starter. I also helped my sister out with her truck. I helped replace her lower control arms, sway bar links, and a few other things related to steering and suspension. She ended up buying me a new ignition switch to compensate me for my time and labor.
- At this point I have a brand new battery, battery cables, starter, NSS and ignition switch. I've spent $437.54 + $52.30 for the ignition switch my sister bought me. This has replaced just about every part in my starting circuit and many of the parts have lifetime warranties which is the only silver lining I can see about this right now. The starter, NSS and ignition switch all have limited lifetime warranties and the battery is 3 year and then a pro-rate for the next 2 years after that. Plus I have the original parts that I replaced for backups just in case. Needless to say, I know at this point I went about this the wrong way. I've learned a lot and if I knew then what I know now, I could've avoided buying all these parts.
Alright so here is the point where I'm at. I can't start the truck EVER. The only way I can start it at this point is to bypass the ignition switch, NSS, relay, etc. I use my jumper cables to pass current from the positive battery terminal to the ignition post on the starter solenoid. As long as the key is in the run position, I can start my truck and get around. This is annoying but at least I now know how to start the truck no matter what. None of this guessing like I did before with rocking the truck and letting it cool off. From this I've learned that the signal is not being sent. I've checked the tan/red wire that comes from the NSS to the relay box. When the truck was starting and I would see ~12V there. Last time I checked without the truck turning on and I saw voltage but I don't think there was at least 12V. I'm not sure if I wasn't making a good contact or what. I also know that the ignition post on the solenoid is not getting power. Tracing this back a bit I had replaced part of the yellow/blue wire but not all of it. The battery cables have an area where this wire clips in. This yellow/blue wire I believe then goes into the wiring harness and to the back of the fuse box/ relay. I also checked the red/blue wire coming out of the ignition switch and I was getting ~12V when the truck would start (cranking) but when I turn the key to start and it won't start, I'm not getting 12V coming out of there. I just checked and I don't think I'm getting power to the ignition switch anymore. I don't think the green/purple wire has any voltage anymore. It's dark and I'm using a flashlight so it's possible the tip wasn't making contact but is it possible I blew that 20A fuse (F102)? It's one of those square fuses that I'm not sure how to check.
**SHORT VERSION**
New battery, battery cables, starter, neutral safety switch and ignition switch. Can anyone walk me through the steps I need to locate the problem? I have the wiring diagram uploaded and I think I understand it pretty well it's just that I'm new to this so not sure what to do. I know the red wire going from the battery to starter is good. I'm assuming the black/orange wire going to the charging circuit is good because my truck runs fine after I start it, I just can't get it started using the starting circuit. Only way to start my truck is put the key to run and apply 12V to the ignition post on starter solenoid. Can someone help walk me through the middle path of the diagram? I tried locating the yellow/green wire the goes from the battery to F102 but I haven't been able to find it yet. I think it might run behind the battery but I'm not sure. I just checked the green/purple wire going to the ignition switch and I don't think I have voltage anymore. I used to have constant voltage there and now I believe it's 0V. Could I have blown F102? I checked the red/blue wire and I don't have voltage either (when cranking). I used to get voltage when the truck started but the truck won't start anymore. I'm assuming this is part of the problem. I've tried adjusting the NSS also but I think it's good. I know that power is not getting to the relay because I don't hear the click. I'm also not getting 12V from the tan/red wire or the yellow/blue wire. Thanks in advance for any help.
http://www.autogenius.info/ford-f-15...e-box-diagram/
02-03-2017, 09:29 AM
#2
05 5.4l 3v s.crew lariat
I have the 05 and diagram
The trouble with jumping relay contacts is to be certain you are on the correct terminals . Its not easy as the view of the socket versus the relay is different .
I believe you are right you must have blown f102 or f101 . I have never taken it out so someone else may tell you how to pull it . It shouldn't be difficult to pull .
F102/101 should be checked first , I don't know if you have an ohm meter or not or how to use one .
Ohms is just to check continuity on a dead circuit . That will check fuses when out of the circuit . Also you should learn to use a fused jumper . If I were there I could show you lots of tricks . It may be best to get some help on the electrical trouble shooting . It takes some experience and its not for everybody . Good luck if you try to learn it without help .
It is hard for me to read all this and make sense of it . But here it goes . I think you may have been right, your starter relay was not picking up but why ? You should see if you get start signal +12v is getting to 86 on the start relay coil tan/red wire circuit . That tells a lot .
But you realize the PCM controls the negative side of the relay . You have to satisfy the PCM to get that . This would be another diagram to troubleshoot .
Run your reference lead to the battery terminal to eliminate a poor reference for your meter . If you are looking for positive 12v then run a neg terminal wire to your meter reference lead , avoid trusting frame connection .
I am confused when you use ~ does that mean neg 12v (-12vdc) ? Not sure .
You need to verify 12v coming to f102 ,f101 from battery yellow green wire .
Find out where you are losing signal . Sometimes a lamp tester is easier to see since it draws some load and is very visual . Maybe fix the blown fuse problem to get back to your original problem . Could be a bad start relay or more likely the pcm is not giving negative signal to start relay because its not satisfied . Start relay will be cheap . But you can test for that .
You may even find that the key you are using is not giving the security code to the PCM ,try using the other original key .
Then there is the rat problem of wires being eaten because of soy in insulation . Lots of possibilities.
From your original trouble it is very possible the start relay contacts are burn't and make only every now and then .
Get back to us .
02-03-2017, 10:49 AM
#3
Update
*Update*
I have uploaded a picture of what my fuse looks like. I don't think they are blown because the metal was not broken and they looked alright. I was able to pull F101 using my fingers and a bunch of wiggling. F102 was a lot harder so I grabbed some pliers and carefully removed it. Both fuses seemed alright and I was getting ~12V on one terminal of each fuse location. The ~ means approximately. I used it earlier because I had over 12V but I was not implying a negative (-). I believe that the fuses are fine and the yellow/green wire is okay. I checked terminal 86 of R01 with the relay out and I was getting around ~10.15V when turning the key to "start". I checked terminal 85 but didn't have anything. Based on this I think I've narrowed in on the trouble area a little bit. At least I think I can rule out the yellow/green wire and F101 & F102.
As far as checking continuity... should I still check for continuity on the terminals of F101 & F102? I forgot to check.... I'll check real quick. Alright so F101 I was not getting any continuity. F102 it showed a -490 but when I flipped the leads I couldn't get a number. Also this number only showed up after the key was inserted.
I have uploaded a picture of what my fuse looks like. I don't think they are blown because the metal was not broken and they looked alright. I was able to pull F101 using my fingers and a bunch of wiggling. F102 was a lot harder so I grabbed some pliers and carefully removed it. Both fuses seemed alright and I was getting ~12V on one terminal of each fuse location. The ~ means approximately. I used it earlier because I had over 12V but I was not implying a negative (-). I believe that the fuses are fine and the yellow/green wire is okay. I checked terminal 86 of R01 with the relay out and I was getting around ~10.15V when turning the key to "start". I checked terminal 85 but didn't have anything. Based on this I think I've narrowed in on the trouble area a little bit. At least I think I can rule out the yellow/green wire and F101 & F102.
As far as checking continuity... should I still check for continuity on the terminals of F101 & F102? I forgot to check.... I'll check real quick. Alright so F101 I was not getting any continuity. F102 it showed a -490 but when I flipped the leads I couldn't get a number. Also this number only showed up after the key was inserted.
02-03-2017, 10:53 AM
#4
I don't believe the relay is bad and I bought this truck used so I only have the 1 key. If the relay contacts are burnt how would I fix that? Would this require removal of the fuse box?
02-03-2017, 11:38 AM
#6
Alright I think making notes on this is helping me solve my problem. I just checked the green/purple wire going to the ignition switch and I had ~12V (approx.) and then I checked the red/blue wire that sends a signal to the NSS and that also had ~12V. This leads me to believe the problem lies elsewhere and I can shorten my target area. I've looked under the truck previously when working on the NSS and the wires are old and dirty so they are kind of hard to see. I'm going to try checking the tan/red wire again. I believe the problem has to do with the contacts where the starter relay goes in.
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Joe Cervantes (11-16-2020)
02-03-2017, 12:46 PM
#7
I feel like I am stuck. I just tested all the small fuses that my truck has (01-42) and all of them have continuity. I checked the larger fuses earlier F101 & F102 which both checked out. I visually checked the other big fuses but I didn't literally pull each one out because they are associated with different circuits.
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02-03-2017, 12:53 PM
#8
I believe my problem lies somewhere between the ignition switch and neutral safety switch or between the neutral safety switch and relay. The trouble I'm having with the NSS is telling which wire is what. If I attach one lead to the red/blue wire coming out of the ignition switch and the other lead to the blue/orange wire going into the NSS can I check for continuity to determine if there is a break in the wire? Is that how this is done? Also would I attach one lead to the tan/red wire coming out of the NSS and the other lead to the tan/red wire located near the fuse to check for a break in that wire?
02-03-2017, 02:39 PM
#10
The truck doesn't start in neutral. I also replaced the NSS so unless I got a faulty one, I think it has to do with wiring or positioning. I found which wires go to the NSS. The tan/red wire coming out of the NSS has continuity to the tan/red wire by the fuse box. I think the rest of the circuit might be good and that the problem lies with the wire from ignition switch to NSS or the NSS itself/position. When I checked continuity from the red/blue wire coming out of the ignition switch to the blue/orange wire going into the NSS I didn't have continuity. I think I might have a break somewhere between ignition switch and NSS. When I checked continuity from red/blue wire from ignition switch to the tan/red wire coming out of NSS it displayed ~1500. I'm not sure what to make of this. If the signal from the ignition switch is never making it to the NSS is there a way to check this? I was thinking if I apply 12V to the blue/orange wire going into the NSS when the key is turned would that tell me if that wire is my problem?