i dont have the cruise or AC features on my truck,
id just like to get my batt charging so i can drive. bad timing for this i gotta leave for the yukon in 4 days.

is there a test i can do to see if my computer is bad?
these are regulated by the computer right?

 

Yes the alt is regulated by the computer. Does your speedo still work?

 

no my speedo is dead but i think its the VSS.
How would i test the computer to see if thats the problem?

 

I am not sure how to test it but with everything that you have not working I would put money on it being bad. Might be cheaper and easier to replace it than it would be to make everything work without it.

 

Just throw an external regulator on there since you have no A/C or cruise. Info in the sticky.

If the PCM has died, you can make the speedo work again by grounding the ground wire from the VSS. The VSS normally gets ground through the PCM.

 

hey thanx for all the help everyone. MUCH appreciated.
i just came on here to post that i put in an external regulator and it fixed the problem. so once again, you were right on the money wanna. thanx again.

What else does the pcm control? id like to eliminate as much from it as i can.

 

oh and also i was wondering where a good place would be to tap into, to get power to the alt when i turn the key.

ive found a couple unused plugs on that side that get close to 12 volts with the key on, but the wires are a bit smaller then the original power supply to the Alt so just was worried about the smaller wire burnin up.

 

Any dark blue wire under the hood will do fine.