If i check power at the red/green wire i should have power with key on correct? My idiot lights dont come on and the fuel pump wont turn on either. The fusable like in the right front next to the battery smoked the other day when i was trying to start it. The truck will turn over but no fire. Is there any other way to check the ign switch? The fuel pump will not turn on either? What controls all this. The schematics arr not much help. Any ideas.

Thanks. Tim

 

That is correct.
This wire feeds the Ignition Coil and the EEC Power relay. So no spark or fuel pump if this wire is dead.
Sounds like the fuse link has opened that feeds the Ignition switch.
Yes but you would have to remove it and test it with a meter.


/

 

What smoked the fuse link, a regular ato fuse pops in a second, a fuse link takes several seconds to burn thru. I would use caution when replacing that link, I doubt the ignition switch did it, there is no ground going to the switch, it might be burned up in there as well, but you need to find the source of what killed the link, thin jumper wire to connect the fuse link first, if it starts smoking disconnect and follow that link to see what it feeds, pull the PCM relay, any fuse that the circuit feeds as well till the short is gone, then start reinstalling till wire starts melting again, than you know what it is.

 

Unplug the Ignition switch before replacing the fuse link to make sure the rest of the circuit is intact.
Note the PCM Power relay does not use much as the red/green wire only feeds its coil. So pulling it will not tell you much unless the coil is shored in the relay itself.









/

 

Ok so i have no power coming out of the ign switch. Not sure what smoked the link. I was just trying to start it and looked up and saw smoke. Thanks for the schematics. I will use them tonight when i get home

 

Add another schematic for the red/green wire to the above array of schematics.
Check around that radio capacitor. Others have had problems with shorts in that area.

 

Ok so i have continuity through the fusable like that smoked. To me its still good right? Everything seems to be he cheking out except the wire from the switch. All the fuses and relays are good and check out. Is there a relay or fuse for the ign system?

 

So i take back my earlier post. Well now i have no power to the eec relay dome lights or the radio. Yesterday i had the radio and dome lights

 

[QUOTE=subford;15328732]That is correct.
This wire feeds the Ignition Coil and the EEC Power relay. So no spark or fuel pump if this wire is dead.

Sounds like the fuse link has opened that feeds the Ignition switch.
Yes but you would have to remove it and test it with a meter.
[IMG]http://i54.photobucket.com/albums/g91/subford/Electrical/1990%20Diagrams/149-02_zpscde2b115.jpg[/IMG


So the fuseable link that grounds to the right front core support would be the ignition link. There are three right there but the one the smoked is the one that grounds right on the core support

 

I have never been so lost on a truck before. Its like i lose more evrrytime i look at the truck. Going to test the ign control module tomorrow and see what happens. I did change out a month ago. Wish me luck

 

The ICM (ign control module) would have nothing to do with your problem.
There are no fuse links going to the core support. If one of the ground wire smoked going to a ground support you need to trace that ground wire back to see what it is attached to.
You should have three ground wires there on the RH passenger side radiator support (G101, G102 & G203) plus a larger ground wire from the NEG battery post.

All of the fuse links are attached to the battery side of the starter solenoid (relay).
You did run the large battery NEG cable to the engine block and not the frame. The frame may also be grounded but the large NEG battery cable bolts to a mounting bolt of the starter.

 

Yes the ground cable is there and tight. The schematic dont show that ground on the core support. Really hoping i dont have to cut that harness open

 

Those 3 black ground wires on the passenger rad support are crucial. They are not fuse links, just black wires that bring ground to there respective circuits. Make sure that a 10 ga lead comes off the battery and grounds with those 3 wires, they have to be clean, rust free and making good contact. you still have to trace that fuselink, or it wasn't a fuse link it was one of the ground wires? Make sure the main ground from the battery to the block is also clean and making good contact, if it's not it will pull ground from anywhere, the drivetrain is isolated on rubber mounts so that fat ground is ever so important, even add another one, to the alt bracket or somewhere easy to get to.

 

I will double check the main ground tonight. Might even add another if i need to. I cleaned them all off before i put them back on and made sure they were good. Thanks for the help yall.

 

Ok so i checked power to the fuse panel and i have power to only a few. Then i checked power to the eec relay and nothing. All the grounds i can find are clean and good. Headlights work and thats it. WTH