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wiring diagram for 1989 gmc k1500

31K views 4 replies 2 participants last post by  surveyor1951 
#1 ·
I have a 1989 gmc sierra k1500 extended cab. When I turn my ignition switch to acc, I have no voltage so I am wondering where the acc white wire goes from the ignition switch. I have very little current from the pink or orange wire (ignition switch) when I have the engine running. I just want to know where these wires go to after the connector that comes down from the ignition switch. Any help on this would be much apprieciated. Thanks
 
#3 ·
The reason I posted was because a screw driver slipped & hit the grd & ignition post of my solenoid for my dual battery set up. Since then my aux battery would not charge. I then checked the voltage at ign post of this solenoid & noticed no voltage coming from it. I then put a jumper wire from the main battery post of the solenoid to the small ign post & then checked the acc battery post voltage & it registered 0v & no continuity between the main battery post & the acc battery post. So I must have shorted it out. I investigated it more & took some voltage tests at the connector for the ignition harness. My findings were:
12V CONSTANT WIRE RED there was no red but white. In acc,it gave me 12.8v, with the engine running it gave 14.5v
STARTER WIRE YELLOW OR PURPLE-the purple wire gave me 0.03v while in acc, with the engine running it gave me 0.71v
IGNITION WIRE PINK-in acc. it gave me 0.03v, while the engine was running it gave me 0.70v
ACCESSORY WIRE ORANGE-in acc it gave me 0.03v, while the engine was running it gave me 0.72v
Gray wire?-in acc this wire gave me 0.03v, while the engine was running it gave me 0.70v

I'm not sure if these are normal readings for the ignition? Are these good? Does anybody know what the gray wire is for? Looking at the wiring diagram the pink wire has a 3amp fuse before it hits the engine control module then to the coil- the white wire goes to the battery & the purple one goes to the starter. I do not know where the gray one goes unless this is the tach, sort of confused with the white & gray wire as the diagram shows the white wire as the tach. coming out of the coil. Just wondering if these readings are normal or did the solenoid create other problems? Any help on this would be much apprieciated. Thanks. Also thanks for the wiring diagrams
 
#4 ·
Is your dual battery setup from the factory or is it aftermarket ? The Autozone diagarm may be incorrect for your truck if it's OEM. If so what, engine did your truck originally come with and I'll see if I can come up with the correct one. Sometimes those third party diagrams are incorrect anyway. Don't recall ever seeing a factory dual battery setup on a 1500. Have you checked the fusible link on the juction block ? On my 1988 Silverado the junction block is under a long plastic cover on the passenger side at the top of the firewall. If you don't know what a fusible link is, it's a fuse that looks like a wire. If that's it, don't replace it with any wire, it must be replaced with the correct fusible link .
 
#5 ·
My truck came with 1 battery only. The solenoid I bought was from the local parts store. Instructions said to hook 14 gauge wire to ign. part of the solenoid & 10 gauge wires from the batteries to the appropriate battery post terminals on the soleinoid. It worked good till my screw driver sorted out the solinoid. The engine is a 350 or 5.7L. I will check out the fusible link. Thanks
 
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