Volt meter driving me nuts

[Fredfox]

My volt meter reads erratic, sometimes below 12 sometimes above 12. No other problems, starts fine, lights good?

[harborman]

Originally Posted by Fredfox

My volt meter reads erratic, sometimes below 12 sometimes above 12. No other problems, starts fine, lights good?

Have you put a volt meter directly on the battery to see if you get the same variation in readings?

[Landseer]

Mine shift depending on level of charge and accessory use. And flick a bit with signal lights. All four cars, including the two with Delco alternators.

But, the 86 went through a period of stucatto movement. Cause turned-out to be a broken wire at a solder joint on either the front or backside of the 14 pin connector. Once we resoldered it was steady and back to the above mentioned pattern. Hope that helps a little.

[harborman]

Originally Posted by Landseer

Mine shift depending on level of charge and accessory use. And flick a bit with signal lights. All four cars, including the two with Delco alternators.

But, the 86 went through a period of stucatto movement. Cause turned-out to be a broken wire at a solder joint on either the front or backside of the 14 pin connector. Once we resoldered it was steady and back to the above mentioned pattern. Hope that helps a little.

Yep, mine does the same. I looked at the schematic and might be a bad connection like you said. It appears it's in the meter connections as the lights and other equipment does not vary from observation at least. Is the 14 pin conn on the control panel?? Normally the meter should read about 13.8 volts.

[Landseer]

They aren't known to be particularly accurate, voltage scale wise.

The 14 pin connector is on the passenger side, inner front fender.

14 pin connector


So, separate issue for just a second. Harborman, have you checked operation of the wide open throttle switch yet? I just adjusted one and it made immense difference. It was acting flat, almost bogging, after heavy throttle upshifts, taking far too long to build rpms after the shifts. This is a hidden failure point that means a huge peformance difference, huge, when you press hard on the accelerator. I think a lot of cars are misdiagnosed as having tired old engines, when its just the bowden cable (for automatics) and the wot that need adjustment.

[JhwShark]

Yes, the 14pin is near/next to the jump post. Some things that improve reliability of meter readings:

Clean the jump post and the 14 pin terminal/connector is one of the tasks. Another is to clean the control panel connectors and fuse block. Then the grounds in the Bat area plastic connector and above the Control Panel and others.

Then if you have some time...pull the pod and take the cluster out, clean the three connectors with the red eraser, take the film circuit off the cluster and clean the metal strips with the white eraser. I have heard that on some models thee is a calibration on the back of the cluster; but not on mine.

Jon

[harborman]

Originally Posted by JhwShark

Yes, the 14pin is near/next to the jump post. Some things that improve reliability of meter readings:

Clean the jump post and the 14 pin terminal/connector is one of the tasks. Another is to clean the control panel connectors and fuse block. Then the grounds in the Bat area plastic connector and above the Control Panel and others.

Then if you have some time...pull the pod and take the cluster out, clean the three connectors with the red eraser, take the film circuit off the cluster and clean the metal strips with the white eraser. I have heard that on some models thee is a calibration on the back of the cluster; but not on mine.

Jon

Ok, sounds good, except I won't attack the Pod for now. I did fix my Fog lights. There are two relays involved, one provides 12V to the other, relays IV and VIII, both had stuck on me. I took them out, put on my bench supply, operated them and got them to unstick. Then polished all contacts and put cleaner spray in fuse panel. I also took out EVERY fuse, cleaned them up, sprayed contact cleaner on all contacts. I am now thinking of removing the rest of the relays and doing same.

[JhwShark]

Me too...I cleaned the panel a year ago due to some corrosion.
But it happened again, corrosion that is. I found after a good rain that all the relays had condensation on the top, a film. I went on the hunt, so I could practice my electronics cleaning skills maybe, only one more time.

Well I knew I had some water somewhere inside. Wasn't the drains above the panel, or the windshield seals or any source up front. I opened the boot and saw some moisture along the cable harness so I pulled up the spare and had a puddle. The hatch latch seal bad, the qrtr windows also had some water under them...

Last week I pulled the trim and sealed the qrtrs on both outside channels, black against the body and clear against the windows. Black around the hatch glass. Reapplied the trim. And new latch seal. Qrtr seals are$$ Mine are degrading but I'll wait for now.

It's raining again but it's dry inside; the car that is. Time to clean the board, fuses, and relays.

[harborman]

Originally Posted by JhwShark

Me too...I cleaned the panel a year ago due to some corrosion.
But it happened again, corrosion that is. I found after a good rain that all the relays had condensation on the top, a film. I went on the hunt, so I could practice my electronics cleaning skills maybe, only one more time.

Well I knew I had some water somewhere inside. Wasn't the drains above the panel, or the windshield seals or any source up front. I opened the boot and saw some moisture along the cable harness so I pulled up the spare and had a puddle. The hatch latch seal bad, the qrtr windows also had some water under them...

Last week I pulled the trim and sealed the qrtrs on both outside channels, black against the body and clear against the windows. Black around the hatch glass. Reapplied the trim. And new latch seal. Qrtr seals are$$ Mine are degrading but I'll wait for now.

It's raining again but it's dry inside; the car that is. Time to clean the board, fuses, and relays.

I only drive my car in dry, nice weather and it's always garage kept in a heated garage. I have other cars to use, so nice to keep the 928S for good driving conditions when ever possible. All those seals will get stiff after all these years, but amazing how well they held up. My car however was in storage a very long time!

[Fredfox]

Had alt rebuilt, seems a little better.