[blacksmokecummins9496]

I took a 95 12valve and put it in my 98 gasser i put in a 98 engine harness with it but for some reason the alternator isn't charging so i put another on on it and still none of the terminals are hot. If anyone has any suggestions i would appriciate it. Also for some reason the tach doesnt work either

 

[ykdave]

the carging is controlled by the PCM. If the PCM does not have a tach signal, it doesnt think the engine is running and it will not charge.

Fix the tach, and it should charge!

Check the adjustment of the crank position sensor/ess and its wiring.

 

[blackimpala]

Not sure of any of this but here gos. The 2gen trucks use the PCM to regulate the Alt. so if you didn't put that in with it you have no voltage reg. But you can use an external voltage reg that came on the older cars. Do a search and you can find a post that tells you how to wire it in wire by wire.

Floyd

 

[illflem]

Click> http://www.cumminsforum.com/forum/9...-external-voltage-regulator-install-pics.html

 

[blacksmokecummins9496]

i used the 98 12valve PCM but i will try getting the tach to work. I very much appriciate everyones help. Thanks