My wife has an 2001 Chevrolet Monte Carlo that sat for about 6 years before she got it 3 years ago. It’s having a few electrical problems.
Temperature gauge doesn’t work. I replaced the sender with a GM replacement and it worked for a few minutes, then cut out again. I checked the voltage and its 3.5-ish, but when I manipulate the connector it jumps to 5 V, so I’m assuming I have to replace the connector ($50 for a 6-inch pair of wires with connectors).
Sometimes it wont crank over. Lights come on, fuel pump turns, gauges come up, but no crank, until I pop the hood. Simply pulling the hood release lever makes it work again.
When she hits a bump, the gauges lose power, engine sputters, runs rough, and will die if you let it idle. However, if you turn it off and then on, it will sometimes work, though opening and closing the hood always makes it start working again.
We have rebuilt the alternator, replaced the battery, replaced the water pump, replaced the plastic intake manifold, and a few other things that I can’t think of.
She tried to have an aftermarket radio installed that never worked, and the stock radio doesn’t work either, they apparently if you open and slam the trunk a few dozen times it will work for a little while. They did a hack job trying to put the radio in, I found wires jammed into the fuse for the pcm, and the main harness sliced open and spliced into for power and who knows what else. So I need to remove all that garbage and see if that helps.
I’m thinking there are grounding issues also, or a faulty BCM or PCM, and I heard something about the crankshaft position sensor possibly causing problems.
Any ideas where else to look?