95 monte with odd electrical issue
 

my 95 monte ls started have weird issues with something electrical. when ever i use anything electronic (blinkers, windows) the gauges jump,and rpms lower roughly 200. seems like all power gets drawn. battery is 12.4v and new alternator is putting out over 14v. Thought maybe it was bad ground so i put hefty wires from battery to engine and body with no change. yesterday overdrive did not work unless my foot was off the pedal. I disconnected battery to try and reset pcm now there is different tranny problem. All the power still acts like its getting all sucked out and the rpms drop to 500-700 when i take my foot off the gas even at highway speed like im in neutral.

Let me know what you think

airbag and abs light are on too. not sure if they are related. Also its the 3.1L

Check your wiring, you could have something that is making **** short out. I know that's a rough task, but you should also check regular maintenance items - PCV, fuel filter, air filter, etc

I say that because using electronics adds a load to the engine regardless and could cause the idle to drop if there is already an underlying maintenance issue

i did check over most wires that were exposed. One thing is that the wheel well cover is missing right by computer and one of the fuse boxes on the passenger side. I thought the fuse box would of been it when i checked it out and it had corrosion on the bottom connections but after i cleaned it there was no change and computer looked as if there was no corrosion.
power can get so low that on freeway when changing lanes the blinker will disengage the cruse control and my cd player will turn off momentarily

Stock CD player or aftermarket? If aftermarket, take it out and check the connections

A buddy of mine had a loose wire coming from his stereo, shorted out the entire harness

Also make sure all of your grounds are good

aftermarket. i did have it out...didnt see anything bad. will check again. I have large cables going to the engine and to the body off the battery cause thats what i was thinking it was at first. is there any sort of ground that goes to the pcm? I looked but didnt see anything

The PCM does have a ground wire, but you'll have to find the pinout for your engine. Or you could just open up the PCM box, pull out the PCM and check the connectors.

Check the grounds by the starter/transmission.

Look over all the exposed wires in the engine bay, one might be missing some coating and it might be arcing

ok i'll check it out. could it be some sensor messing with multiple things??

Indeed it could be. Wiring problems & sensor problems are the worst, especially when they don't throw a code.

I havent looked at anything yet cause I'm at work but does anything else come to mind that I could check