merchauser

OK, somewhat good to hear.....strangely, I was hoping to hear those numbers under load were bad

so my thinking that some compensating circuit should be keeping the voltage even with no voltage drop is off base?

i read a post regarding a 1984 and a way to calibrate the dash volt gauge, is it possible to calibrate the gauge the same way in my 1990?

Chalkboss

It is possible to calibrate the gauge, at least in my 87. It was reading about 1v low, had it all apart and had my friend connect a 12v power supply to it, and adjusted a pot on the back of gauge. It's a little wonky right at 13 but fairly accurate at 12 or 14v now.

FredR

The voltmeter is infamously inaccurate- what you are looking for is a trend. They can easily be out by +/- 0.5 volts or more but what does that really matter? Take a digital meter and read the voltage at the hot post. Know that it will be a tad lower on the main bus in the central electrics. Compare that to the indicated value and apply that difference across the board.

terry gt

I had a issue with low idle with A/C on along with a couple of other issues that I did not realize
turns out to be the jump post
looked perfect
soldered the main power wire terminal and polished the two small red wires
BIG difference everything ran better

merchauser

thanks Terry
my connections at post look great, but nonetheless, I will clean them up.

lucky for me, I have not experienced any drop in RPM with or without AC on

Fred, don't you think there should be a smoother transition when I depress the clutch? the end result is that the car recovers nicely, but only after a bit of a gulp. I just have to (want to) believe that there should be no noticeable transition

I see many posts that say the Temp II switch should be replaced like an air filter, so thinking of doing that for the heck of it.

not prepared to take out the pod and instruments just yet, so I will live with the inaccurate gauge. volt meter told me what I need to know.

FredR

When you are changing gear in a manual you roll off the throttle, the revs die to idle while you change gear and then you pick up the throttle in the new gear. The alternator is directly driven from the crankshaft and the alternator speed drops directly with the engine speed. Your load is still connected but the power is not there, the voltage drops to support the amps demanded. The battery can only supply so much and then its voltage drops as the thing becomes more stressed. This is where battery sizing kicks in [that and starting load].

Thus what you are seeing seems voltage wise seems perfectly normal. if it is really bugging you folks like GB and Carl sell higher output alternators that will more or less make such phenomena a thing of the past. Remember our stock alternators are old tech designs and newer designs can pump out more juice for a given frame size.