Tim Murphy

I had a similar issue with my 87 that I chased for quite some time. It was an intermittent low voltage situation that would mess with the computers.

Long story short, the 2 smaller gauge wires that connect at the battery positive post were only finger tight. Tightened it up and problem solved.

BTW, these wires feed direct to the fuse box to power the computers. Not totally sure, but I think they might feed the voltage gauge too.

dr bob

Voltmeter feed is from the 15 bus, on when key is in 'run' position. The ignition switch feeds from the 30 bus in the CE panel, which feeds coming from the battery to the starter, on to the alternator, and on through the jumpstart post in the engine bay. So the loose secondary feeds on the battery positive should not affect a voltmeter reading in the dash, at least not directly.

On my '89, two of those smaller feeders supply the cooling fans. There's also a feeder that supplies the EZK, LH and fuel pump relays, plus keep-alive power to the brains themselves. This moves the brains away from alternator hash, with the very low-impedance battery located electrically between the alternator and the brains in the circuit. More than a few casual intermittent fan and LH/FP 'problems' have been cured by cleaning and tightening those little wire connections at the battery positive terminal.

The WSM diagram shows more wires connected to the battery than I actually see on my car, a total of seven. I have three smaller red wires plus the main battery-to-starter cable for a total of four.

DanielD

I checked the belts, the battery connections; no problem noted. It ran to spec yesterday and again today. The weather was really nice today so I took it out for a spin, about 130 miles, with no issues. Turned it off and cranked it 6 times today total with nothing noted. It's gonna show up again at the worst time, I just know it.
I think too, that it is in the charge circuit. Something is intermittent.