I don't think YOU understand. YOU came HERE for help, I'm offering you a suggestion based on what I've dealt with. If you can jump that relay and it starts it usually means either the relay is bad or wires going to it are bad. **** breaks for absolutely no discernible reason all the time. Just because it worked BEFORE doesn't mean it is right now.

I've dealt with ones that for whatever reason were bad right out of the box, it happens. Just check it and know for sure its good or bad instead of assuming its good. Buy a new one. Either it fixes it and awesome or it doesn't and you return it and get your money back.

The symptoms match the potential problem, as far as my knowledge goes.

 

So my dad has a 93 5.0 aod and a 94 4.9 e4od and I have a 95 4.9 m5r2 and all three have bad relays or wires going to them because you can jump them and all 3 start?

 

Its possible if none start normally but start if you jump the relay. Same symptoms have pointed to that on two different friends cars, one of them three different times, friends grandpas truck, brothers 2 cars, moms different cars over the years, and plenty of other vehicles I've worked on.

if its a strong possibility and replacing it could fix it, why not just try. Like I keep saying its based on my experiences.

 

They all start normally, you said they have bad relays or wiring if you can jump the relay and they start. I went outside and took a screwdriver and jumped relay on all 3 and they all started. Are you saying I should replace all 3 starter relays?

 

No, I said if they don't start normally (like you say your truck doesn't) but everything else functions normally and they start if you jump the relay, then the relay or connections are most likely bad.

 

Okay read carefully, the truck I am talking about is a 93, of a friend. My truck is 95 factory 5spd. I took the (working) starter relay off of mine and put on his. You still had to jump it to make it crank. I put starter relay back on my truck, it started with key. Took the harness off mine for starter, battery, and relay. Connected to his, still had to jump relay. Put back on mine, started with key. Did this with the column, key switch, clutch pedal switch, trans harness, computer, starter, relay, and installed on mine it started with key. Put all mine on his, have to jump off at relay. Switch everything back and same thing. You're telling me that this is still something to do with the relay because it can be jumped to start?

 

Your original post

So does it crank and no start or not crank at all?

So basically you've been constantly swapping donor parts from the receiving truck back into the donor truck and back again to test them?

So either you f'ed up the wiring somehow or something between the key and that relay happens to not work on the truck.

I will repeat, again, based on MY experience that if you get power but no crank that either the relay is bad or something wrong with the connection TO the relay. That's if it's not cranking. You posted before that you changed the key switch and it cranked but wouldn't start. So which is it? They point to different parts.

You've already been told by someone else to start checking your wiring.

If you know 100% that the relay is good then check the connections and wires because obviously something isn't doing its job. Are all the wires on the relay in the proper places? Have you done voltage tests to make sure power is getting TO the relay? Have you checked the wire and connection that operates the relay?

You want another suggestion? Check every wire on your ignition switch, the one bolted to the steering column. Does it look like this?



If not, find a schematic that shows yours. Make sure all the power wires have power and that its getting where its supposed. Obviously the focus being that power is getting to the wire that actually starts the truck. Is the "starter" wire getting power? Yes, then follow the wire to whatever it connects to and make sure power is getting to the corresponding wire on the other side of that connection and so on until you're at the relay or you find a loss of power.

After I get back home tomorrow I'll double check the schematics for my truck and do some quick tests with my relay and the wires connected to it and then share what I find so you can test yours. Granted I have a 5.0 and this is a 4.9 so I don't know what, if any, differences exist in the wiring of the relay.