Electrical Gremlins in 05 Lariat!
03-09-2015, 12:08 AM
#1
Electrical Gremlins in 05 Lariat!
To start off I have followed the forums for a long time but this is my first time making a post, curious if anyone else has experienced similar issues with their truck.
To introduce the truck, she is a 2005 Lariat, 5.4 V8 with 340,000 kilometres on her still driving strong. Super Crew, 5.5 box & black on tan interior.
This scenario started about a week ago. Up here in Ontario we had a warm sunny day so she got a good wash. Night came and the temperature dropped, I was out for a night drive when out of nowhere the horn started honking intermittently. Pulled in to an empty parking lot and the horn turned to a deeper pitch and burned itself out. I get home and none of the interior lights/3rd brake light will turn off. No matter what position the light switch and dimmer are in, they were on. Had to disconnect battery at night, re-connect in the morning, disconnect at work, reconnect for the drive home. Two days of this and all of a sudden the interior lights/3rd brake light finally turn off.
The next day, my headlights, tailights, gauge cluster, interior lights, windows and radio will not turn on whatsoever. I have had to drive gauging speed on the flow of traffic for the past few days, and any night driving is out of the picture. Basically all I have left that is working is the A/C, heated seats, turn signals and reverse lights. Truck starts up completely fine first crank every time and drives normal. I'm confident this is purely an electrical issue but have no idea where to start looking.
Since i purchased the truck as second owner with 70,000kms on it, it has had odd electrical bugs creep around from time to time. Last winter the sunroof demonically started opening and closing by itself in the middle of a blizzard. Did it randomly for two days, and has never happened since. Every couple months it will be flickering lights, horn honking itself or windows not rolling up. It sounds like a hell of a gremlin but none of these problems have lasted longer than a day or two until now.
Any help would be appreciated, if anybody has a suggestion I am willing to try whatever I can at this point.
To introduce the truck, she is a 2005 Lariat, 5.4 V8 with 340,000 kilometres on her still driving strong. Super Crew, 5.5 box & black on tan interior.
This scenario started about a week ago. Up here in Ontario we had a warm sunny day so she got a good wash. Night came and the temperature dropped, I was out for a night drive when out of nowhere the horn started honking intermittently. Pulled in to an empty parking lot and the horn turned to a deeper pitch and burned itself out. I get home and none of the interior lights/3rd brake light will turn off. No matter what position the light switch and dimmer are in, they were on. Had to disconnect battery at night, re-connect in the morning, disconnect at work, reconnect for the drive home. Two days of this and all of a sudden the interior lights/3rd brake light finally turn off.
The next day, my headlights, tailights, gauge cluster, interior lights, windows and radio will not turn on whatsoever. I have had to drive gauging speed on the flow of traffic for the past few days, and any night driving is out of the picture. Basically all I have left that is working is the A/C, heated seats, turn signals and reverse lights. Truck starts up completely fine first crank every time and drives normal. I'm confident this is purely an electrical issue but have no idea where to start looking.
Since i purchased the truck as second owner with 70,000kms on it, it has had odd electrical bugs creep around from time to time. Last winter the sunroof demonically started opening and closing by itself in the middle of a blizzard. Did it randomly for two days, and has never happened since. Every couple months it will be flickering lights, horn honking itself or windows not rolling up. It sounds like a hell of a gremlin but none of these problems have lasted longer than a day or two until now.
Any help would be appreciated, if anybody has a suggestion I am willing to try whatever I can at this point.
03-09-2015, 12:13 AM
#2
Check your BCM or Body control module, A lot of the stuff you are talking about seems to go thru the BCM. In the Super Crew I think the BCM is behind one of the rear seats. Also there is a chance you have a leaking back window and when you washed the truck water managed to get into the module and cause some short circuts.
The following 2 users liked this post by izzysplace:
fivefourlariat (03-09-2015),
getterdun (09-29-2022)
03-09-2015, 12:20 AM
#3
Check your BCM or Body control module, A lot of the stuff you are talking about seems to go thru the BCM. In the Super Crew I think the BCM is behind one of the rear seats. Also there is a chance you have a leaking back window and when you washed the truck water managed to get into the module and cause some short circuts.
03-09-2015, 12:29 AM
#4
Senior Member
I'm also thinking water leak. Along with the rear window, the third brake light is known to leak and can drip down the back of the body. There are also a few spots at the front passenger side that can allow water to drip onto the fuse block. Pull up the passenger side door sill and see if there is any evidence of a leak.
03-09-2015, 05:28 AM
#6
Moderator (Ret.)
I'm also steering towards the BCM, with a wter leak shorting it out. Strange though that it happened all of the sudden after awhile of ownership, but perhaps the washing and then sudden drop in temps that night caused a rubber seal to shrink up, and water got into a wiring connector.
12-31-2018, 05:58 PM
#7
Junior Member
Join Date: May 2014
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
Interesting. I have an 04 FX4 super cab and I started the relationship with, no windows working, no interior lights, no dash, no crank, and the key on making the antitheft light blink like a ufo. The only working seemed to be the power mirrors and the locks. (Headlights too) I figured id check all the fuses like everyone else. All good. Started getting into the wiring diagrams and found out the windows go through the cluster. Same for the dome lights. Same for the CAN/Bus for the security. Checking by feeding circuits identified that they were able to work. Finally was checking the 12V+ into the cluster, all good. Checking all the 12V- into the cluster, one bad, (Right wire upper clip last pin). Put a ground to it and now everything has come back, even the security. Might work for you?
I pulled a pin diagram off the internet for the 2 connectors to the instrument cluster and combined with the Haynes manual wiring diagrams I was able to locate and identify my problem. Anyone else have this issue?
I pulled a pin diagram off the internet for the 2 connectors to the instrument cluster and combined with the Haynes manual wiring diagrams I was able to locate and identify my problem. Anyone else have this issue?
