john's '81 mouse

Last weekend I started the '81 and took it for a drive to warm her up, before oil change prior to putting her in winter storage, and while driving, I noticed that the Amp Gauge was on the negative side (not normal), and then it would intermittantly go completely to the left / discharge side, then finally whent completely left and stayed there, with no movement at all........great!

So went home, pulled the alternator and took to the local auto parts store for testing, which showed it to be working fine. When reinstalling I noticed the new two wire pig tail I installed 3 years ago, pulled out on the hot / red wire side. Discovered I had done a bone head install back then using those crimp connectors, so I completely removed the pig tail from these two crimp type connectors and soldered the pig tail on, using heat shrink to cover the repaired connections. I installed the alternator and started the engine up, thinking I'd found / fixed the problem, only to find the Amp gauge still clear to the left side, still with no movement at all.

Decided the heck with it, don't have anymore time to fool with the thing, so I changed oil and filter, and drove the vette 130 miles the next day to my mom's garage for winter storage. Car ran fine the whole way, dispite the non functioning Amp gauge. I stopped and started the car several times and seemed to have plenty of battery power. So I assume my electrical charging system is operating OK, and I simply have a gauge or gauge connection problem.

Any thoughts on how to trouble shoot and what to look for when I pull the '81 out of storage next April?

MikeC

Are you sure its not a Voltmeter. My 78 is a voltmeter, i thought ammeter's were in the earlier C-3's

Anyways, if you car is still running after a 130 mile drive, your charging system is fine. Your gauge has a problem.

UKPaul

John,
Assuming that you mean the Voltmeter, then I've had all of this with my '81. Does the Gen light stay on, does it come on with ign. on & engine stopped? My problem was the connector in the back of the gage console making a bad contact with the P. circuit tracks and/or one of the tracks was broken in the illumination circuit. The connector to the speedo/tacho p. circuit was also bad. After I fixed it all, I worked out what break caused what problem, but have since completely forgotten it all (think it's my age :rolleyes: ). It may also just be a dead gage. Either way, I'd pull out the gage console & check it out with an AVO. Pulling it out & disturbing everything might also cause other problems, so it would be a good idea to make sure that the copper tracks to the connector are well glued down to the P. circuit & also very clean. Also clean up the contacts in the connector itself & bend them very slightly out. I did this with both my P. circuits & connectors (as well as fixing the broken track) & all the ****ly little electrical problems were solved.
Good luck
Paul

john's '81 mouse

Paul, thanks a bunch for your response, yes I was talking about the Voltmeter, guess it's my age showing calling it an Ampmeter.

The generator light doesn't come on or work in my '81, I know the bulb is OK, but believe something in the circuit board is bad, but never bothered me much that it didn't work, since the gauge always showed me what I needed to know, until now that is.

I know what you're talking about with the gauge cluster connection. I've had mine out a couple of times. Once to install new heater core, (and do a ton of other 'stuff') and a 2nd time to fix my inoperative oil pressure gauge situation. (After a new oil pressure sending unit, and trying another guage, I found my problem to be a bad connection at the 'el-cheapo' connector the General decided to install on these gauge clusters. I did some cleaning, bending and glueing at that time, but may need to do again........gosh I really don't like pulling this and working on it again, seems like every time I do, I end up breaking something else in there, since the plastic seems to get more brittle with age..........oh well........just have to remember it's all part of the 'fun' of the hobby.

Thanks again for your response, seems like someone out there in the forum has always already dealt with most of my vette issues, so I always appreciate the benefit of their knowledge and experiences in both diagnosis and problem solutions.

UKPaul

John,
It's nice knowing that I'm not the only one who's scared of touching those gauge cluster connections! Since I fixed mine I've avoided going anywhere near it :) (but I've just ordered new air vents for the gauge cluster - time to bite the bullet).
The Gen warning light bulb has one connection to the battery live & the other to the alternator o/p, so if 12v isn't present from the alternator then current will flow through the bulb. I've got an oil temp gauge fitted instead of a clock(?) and the p. circuit for the original clock had just been bent up & rested against the side of the oil temp gauge. After 20 years of vibration/bumps/etc the very thin track in this part of the circuit had broken at the point of the bend. I think this is what caused my Gen light to stop working (or it might have been what caused the choke to stay on?). I repaired it by separating the two plastic parts of the circuit in the area of the break & then jumped the break with low melting point solder. Just to be sure I then soldered a wire across it as well (it's not pretty - the NCRS would have a fit if they saw it :lol: ).
After "buzzing" every track out (make sure all bulbs are removed when you check for continuity), I then glued the two plastic "sheets" together at every point where they were separating. This made the whole of the p. circuit much more rigid & will (I hope) prevent tracks breaking in the future. The connector on the back of the tach/speedo p.circuit was also bad & the gauge cluster still had problems until I fixed that as well, but once you've pulled both clusters out everything becomes a lot easier to suss out & fix. With both clusters out there is enough room to pull the connectors out of the dash & plug them into the clusters so that you can check that everything works before bolting it all back together (am I glad I did that! As you say, fix one thing & something else goes wrong).
About a week before I pulled mine apart a local garage brought me a p. circuit out of a 1 year old Peugeot, with 3000 miles on the clock, as it had a broken track that needed fixing. Just shows that it's not only our old Vettes that have problems with p. circuits (it also let me practice fixing them on someone elses car before I did mine :D ).
Good luck with it, but I've gotta say that it was the most fiddly, infuriating, frustrating & annoying job that I've ever had to do on the Vette :cuss
:cheers:
Paul

Dalannex

I guess Paul took care of the answer I had to your question, so I'll leave it be. I too had to spend some pretty serious time refurbishing my printed circuits when I had my dash apart to do the heater core. Of course, I've done this in a couple of pickups before, so it was nothing new. I am of the opinion these printed circuits are pieces of s**t and that the general really took the cheap way out on them. Oh well, I guess that's what we got, so that's what we have to work with. Let us know what you find out with the gauge. :cheers:

john's '81 mouse

Dalannex:

I sure agree with you assessment of the 'General's' circuit board / connector design as being a piece of s___t. From time to time, I've had the thought of trashing the whole board / and goofy connector, and just hard wire the gauges and light bulbs in the cluster, making sure to have enough excess wire to allow me to pull the cluster out to disconnect the wires for removal of the cluster if necessary, but I never really went any further developing or investing this possibility. (Maybe this would be just a little too much of a Bubba fix for me.) I suppose the General's way was cheaper and allowed for faster assembly line installation, and that's a big part of the game with auto manufacturing efficiency.