Heres my issue, I hook up a manual override to my fans by spiceing into the ground wire for the fans going into the ecm and putting a toggle switch on it. By doing so, the fans kicked on but my volage gauge shot down to the 8 mark. I then unhooked everything i had just installed, ever since my voltage guage will bounce when the turn signal is on, and when i pull the lights on it will drop to about 10 volts and slowly come up to 12. when i start the car in the mornings it will read 14, by about 2 miles it will be at the 10 to 12 range and stay there. Now Ive replaced and or tested the battery, alt, starter, battery cables, ecm (but not prom), buss grounds(both sides), cleaned battery ground. STILL have this issue, Im not sure what else to do or check. Ideas anyone?

Was everything OK before you hooked up the fans switch? Why did you hook up the switch?

Yea It stayed a steady 14.2 before I hooked up the switch. I hooked the switch up to keep her alittle cooler in drive-thrus and slow crusin. I thought it was a good idea.lol

there are relays that control the fans, all you did was ground the relay to pcm wire? thats what the pcm does that shouldnt be an issue. did you clean your engine grounds or power cables?

as far as the cooling it doesnt need to be manually controlled you just need to clean your rad and condenser fins from the back with simple green and a garden hose. or the thermostat and coolant could need changing

Hard to say exactly what your problem is, but the obvious conclusion is the work you did caused it. Go back over every single part of what you did and look for something not right. The problem is there.

What i did was that i ran a wire from the ecm(fan positive wire) to a switch and grounded the other side of the switch, when i flipped the switch it dropped the voltage to 8volts and has had an issue ever since. I did unhook everything i did and have cleaned and replaced everything i could think of, including battery,battery wires, starter, alt and ecm. could it be that it hurt the prom? going to get a used 95 ecm and prom tomorrow.

there are two negative outputs from the pcm to the fan relays, im guessing you only did one but grounding either would not hurt your car in any way

Is there a way to have a garage check my electrical system, Like a tech 2 computer. Also wondering if my gauge is just bad?

nothing that technical on a 95. really you could just clip meter leads to the battery and monitor the meter and inside meter at the same time. most gms dont have very accurate gauges to begin with. yours really sounds like most every bonneville voltage i have seen or herd about. i bought mine a few years old and it has done that the whole time. there are write ups on here about adding a sense wire to it to stabilize it but it hasent bothered mine its on its original alt that has almost 200k

It'* just strange that it didn't start doing that until I tapped into the ECM wire. Can you add a since wire to a single wire alt plug? I seen danthures write up on it yesterday but essential sure if I could do that. I've had a meter on the battery while the turn signal was on and the cars gauge was bouncing but I didn't see a change on the meter on the battery which kinda makes me think its the cars gauge. That'* bad.