Just got a 1992 GMC Sierra 3500 dually w/454. Trying to get the electrical wiring corrected. Alternator is not activating to charge battery.

[MarvinWoodie]

So here's my dilemma. #1 Instrument cluster is out (not working). #2 alternator is not charging the battery, after being replaced. #3 trying to identify the wires on the power block located on the passenger side firewall. #4 last but not least I have a check engine light that stays on the whole time the vehicle's key is active. But I don't have a battery or charging light. Vehicle will start and run. Any help would be greatly appreciated.

 

[dbrannon79]

Welcome @MarvinWoodie

I would start with checking all of the fuses in the fuse box and fuse links on the terminal block on the passenger side firewall using a test light.

once all is verified, then check for power at the back of the alternator.

I assume the engine is throttle body fuel injection, for the check engine light, you can pull codes by using a paper clip on pins A and B. Here is a link that shows you all of GM's basic codes and how to read them using a paper clip.

Full OBD1 Code List And How To Read Them At Home

In this guide, we will go through everything you have to know about OBD1 Trouble Codes. Learn to read the trouble codes without a scanner and the meaning.

mechanicbase.com