Instrument glitches - Fuel gauge/lights

[Aaron65]

I've noticed on my '63 that when the lights are on, the fuel gauge drops to zero, and when the blinker is on, it drops to zero in time with the blinker.  My first thought is that it's a ground issue - is there a dedicated ground wire for the cluster or is it simply grounded through the attaching screws/bolts?  Any other ideas?  

This is a North Carolina car and I'm going to say it sat in a damp climate a lot of its life, so I think I'm going to be dealing with a lot of small electrical issues.  Part of the job...   

[1965rivgs]

  Could be an issue with the printed circuit behind the dash cluster...but first it`s best to be sure the body is properly grounded. There should be two ground straps which are attached to the rear, studded head bolts and extend to the firewall. The ground straps complete the return to battery ground for the body.

  There is also a dedicated dash ground wire which is located on the metal dash support upright to the left of the radio. The ground wire should be either black/white stripe or black and is secured under the fastener that mounts what looks like a relay but is actually the buzzer for the speed minder function.

Tom

Edited November 10, 2022 by 1965rivgs (see edit history)

[Aaron65]

Thanks Tom, just one more thing on the list as I resurrect this old thing. 

[Jim Cannon]

Your suspicion is correct, the ground wire to the printed circuit board is not good.  So the things on the printed circuit board are using the other items on the board for their ground.

 

There is a big round plug on the back of the instrument cluster that plugs into the printed circuit board. One of them is the ground wire.  It is not easy to get to the plug.  I remove the dash pad and get to it from above. Just removing the plug and reinstalling it may clean up the connection. Or spray a little contact cleaner in there, remove and replace multiple times, then wipe everything down and reinstall plug.

 

 

[Dundee]

7 hours ago, 1965rivgs said:

  Could be an issue with the printed circuit behind the dash cluster...but first it`s best to be sure the body is properly grounded. There should be two ground straps which are attached to the rear, studded head bolts and extend to the firewall. The ground straps complete the return to battery ground for the body.

  There is also a dedicated dash ground wire which is located on the metal dash support upright to the left of the radio. The ground wire should be either black/white stripe or black and is secured under the fastener that mounts what looks like a relay but is actually the buzzer for the speed minder function.

Tom

Tom 

I found just 1 ground strap in my kit (keep one throw the rest way PO). Is the firewall connection a bolt, stud or self tapper? I have been looking around but nothing certain!

Dundee

[XframeFX]

9 hours ago, Aaron65 said:

I've noticed on my '63 that when the lights are on, the fuel gauge drops to zero

1st order is to check the ground or provide a temporary ground in troubleshooting.

Impossible to do without removing the fuel tank but, adding a ground wire to the pickup/sender is a good idea.

What condition are your fuse clips? They might be severely rusted being an eastern car.

 

For 1963 production, Buick switched to an "afterjob" instrument panel harness. I am thoroughly familiar with both. By comparison, the mid-year harness is much better in my opinion even if my original early harness wasn't hatched from it's early days. It made me wonder why it needed patching up in the 1st place? One area was the ignition switch in that the connector was severely deformed from melting and totally useless.

 

I found a mid-year harness from a parts car. It too required work before installing. Look at the fuse block to identify a mid -year harness. The early harness had no circuits in the middle.

[1965rivgs]

1 hour ago, Dundee said:

Tom 

I found just 1 ground strap in my kit (keep one throw the rest way PO). Is the firewall connection a bolt, stud or self tapper? I have been looking around but nothing certain!

Dundee

Hex head sheetmetal screw with an oversize flat washer (like a fender washer). Hex head is 1/4 inch

Tom

[Aaron65]

1 hour ago, XframeFX said:

1st order is to check the ground or provide a temporary ground in troubleshooting.

Impossible to do without removing the fuel tank but, adding a ground wire to the pickup/sender is a good idea.

What condition are your fuse clips? They might be severely rusted being an eastern car.

 

For 1963 production, Buick switched to an "afterjob" instrument panel harness. I am thoroughly familiar with both. By comparison, the mid-year harness is much better in my opinion even if my original early harness wasn't hatched from it's early days. It made me wonder why it needed patching up in the 1st place? One area was the ignition switch in that the connector was severely deformed from melting and totally useless.

 

I found a mid-year harness from a parts car. It too required work before installing. Look at the fuse block to identify a mid -year harness. The early harness had no circuits in the middle.

The fuse clips are rusty; my current plan is to hit them with a small Dremel wire wheel to clean them up (if I can).  The car has both engine to firewall grounds. 

Edited November 10, 2022 by Aaron65 (see edit history)

[1965rivgs]

26 minutes ago, Aaron65 said:

The fuse clips are rusty; my current plan is to hit them with a small Dremel wire wheel to clean them up (if I can).  The car has both engine to firewall grounds. 

Clean bright and tight is the rule of thumb I use for electrical work! But I dont think that will affect your ground issue....

Tom

[Aaron65]

2 minutes ago, 1965rivgs said:

Clean bright and tight is the rule of thumb I use for electrical work! But I dont think that will affect your ground issue....

Tom

Yeah, I don't think so either.  I'm going to collect some dash bulbs before I remove the dash pad to get at the plug/ground.  

[1965rivgs]

1 minute ago, Aaron65 said:

Yeah, I don't think so either.  I'm going to collect some dash bulbs before I remove the dash pad to get at the plug/ground.  

  As long as you have the dash pad off be sure the ground wire on the metal upright I mentioned previously is secured.

Tom

[XframeFX]

5 hours ago, 1965rivgs said:

As long as you have the dash pad off be sure the ground wire on the metal upright I mentioned previously is secured.

Tom

I was looking through my files for something else Riviera and found an image of my parts car harness, a mid year 63.

I zoomed in to the Speed Minder buzzer and there it is. A black wire with white stripe to ground to the bulkhead left of the radio.

This might help:

[1965rivgs]

10 hours ago, XframeFX said:

I was looking through my files for something else Riviera and found an image of my parts car harness, a mid year 63.

I zoomed in to the Speed Minder buzzer and there it is. A black wire with white stripe to ground to the bulkhead left of the radio.

This might help:

John,

  That is the wire/dash ground.

Tom Mooney