Pcm Question '92

[Crooked7s]

Hey guys, this is my first post, but I have been searching and reading this forum for a few years now.

I acquired a 92 dodge (see sig below) cheap because it wouldn't charge. I replaced the alternator and PCM. Then replaced the ducks foot with maxi fuses etc. in that order. My question is: after I replaced the PCM, the PCM would continue to hum after the key was turned off. After I rewired everything today, the PCM continues to hum with the key off. If I pull the neg battery terminal it stops obviously. If I pull the 30A fuse for Circuit A14 the hum will stop. It takes me cycling the key to get it to start humming again. It doesn't seem to time out. Is this normal?

Thanks.

[Crooked7s]

I'm wondering if I just have a bad or malfunctioning ECM.  It's a reman from O'Reilly's.  Can anyone with a 1st Gen please see if their PCM has a hum to it after you cycle the key?  It's not very loud, but noticeable with the hood up.  

 

Thanks,

Ian

[mulcher812]

I've never herd of a hum but if i remember correctly the first Gens had a voltage regulator for the alternator and when they start to go bad they hum its a thin silver box with a triangle connector and 2 wires one green and one blue. I would check that and see if it is loose the body of ii is the ground and sometimes when they come loose they don't get a good ground and can cause charging issues and some weird voltage issues. If you have a volt meter check the batteries and see if you have 13-14 volts at the battery with it running.

[Crooked7s]

Thank you mulcher812.

I ordered a new pcm, replaced it last night, and that fixed the problem. Now that all the electrical problems are fixed.....onto everything that is leaking. The joys of having a truck sit for 2 years.

[mulcher812]

glad to help out so how much was the part that you bought?

[Crooked7s]

If I remember correctly, a new PCM was $250.