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1963 Instrument Panel Light Question


Guest DLT

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Hi Dalton here,

I've owned a 1963 Riviera for about 2 months now. Lots of work to date and beginning to make some progress with maintance and repair items. I do have a manual and have studied it extensively BUT I'm not a skilled mechanic.That said, I am trying to do all the work myself.

I've observed a few odd things with the instrument panel lights and hoped someone might have a clue or two about possible solutions.

When the headlights are on there are no insturment lights unless I turn the reostat all the way up. When the lights are on, the "red" bright indicator is dimly illuminated. As background, the previous owner (a ROA member) mentioned that he did not like the Guide-o-Matic so he by-passed it and ran a different headlight bright switch as well. Brights do seem to work alright most of the time but sometimes the dimmer floor switch has no effect - I'm assuming it's dirty and not making contact.

When the reostat is all the way up, then the following is observed: Some of the dash and instrument lights come on, i.e. shifter, light over the AC/Heat controls and at least two of the insturment panel lights (speedo and clock but the clock has no power at this time on that circuit - I assume the other bulbs are burned out). BUT both blinker indicators turn green and the gas gauge moves to E immediately. If I remember the manual correctly, it seems the gas gauge has lost it's ground as I believe that F is full ground (but perhaps I have it backwards). If I turn the reostat off full, then the lights go off and gas gauge returns to previous position.

The other odd thing. When the headlights are off but a turn signal blinker is on, the gas gauge drops about a 1/4 tank and bounces as the blinker cycles.

Another piece of data. The previous owner had a nice collection of spare parts he gave me with the car. One of those parts was a spare circuit board for the panel lights. Maybe I should ask him about that as well???

Any clues as to why I might be getting these odd things happening when I can get the reostat switch to light the panel lights?

PS - One more while I'm listing questions. The speedo bounces but only around 1 to 10 MPH then by 15 to 20 MPH it's smooth. I've not yet tried pulling the cable and lubing but wanted to know if I should check something else.

Thanks in advance.

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Dalton,

If I were in your shoes, I think I'd get rid of the "by-pass" the previous owner put in and go back to scratch. Can you recall if their was a technical problem with the guide-matic or if the owner just didn't like it. Mine is not enjoyable when it raises and lowers the hi beams everytime I go under a street lamp. There's a reostat on the back of it that allows you to turn it off or adjust the sensitivity. There's also an over ride built into the floor dimmer. Depress it half-way and you can over ride the guide-nmatic.

I would imagine that the owner tied the new switch into a circuit and creates a ground issue that affect the other lights.

Good luck on this one.

Ed

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I agree with Ed that it sounds like a bad ground on your instrument panel board. A large plug attaches to the back of the board, from the wiring harness. One of those wires is a ground. You could try jiggling that plug and make sure it is seated well.

One of the neat things about ground wires is that you can always just add another one. Find a ground point anywhere on the panel and add another lightweight wire from there to any other screw or nut under the dash.

I don't think you have to undo the previous owner's work to fix this.

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  • 2 weeks later...

Thanks Jim and Ed,

Due to the fact the previous owner supplied me with many extra parts, including a NOS circuit board, I was able to study the board and discovered that one of the 3 brass mounting connectors felt as if the mounting screw had snapped off and therefore was not making a good ground (these are also 3 individual grounding circuits in addition to the ground on the main plug - not all the ground connect to one another as far as I can tell). The reason I think the screw had snapped off is I could not get a new screw to tread, it felt as if something was blocking it. So I tapped into the ground circuit on the board and now ALL the dash lights work!

If anyone wants a picture of this board for your reference, let me know - being able to trace the circuit made all the difference as all the lights not working were on the same ground circuit!

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  • 5 years later...

Hi Ed and Jim Cannon,

I know this is an old thread but my instrument panel cluster lights on my recently acquired '63 don't work either, except for the Amp and parking brake lights, light, turn signals, and high beam. I removed the headlight switch and it looks to be new; the rheostat is not perfect (not corroded) and I even tried what I see you recommend often and cycled the dimmer-twist function many times to see if this helped. I then pulled the 3A fuse and saw that it was blown. I replaced it and the new fuse blew right away so I must have a short. Two initial questions before I start my detective work:

1. The driver's side door jamb switch does not appear to be working. I ordered one from Clark's Corvair. Could that have anything to do with the IP lights? I read your threads on the three circuits that the door jamb switches control, but would a short or ground affect the IP cluster circuit?

2. Should I try and establish a new a ground from the printed circuit? If so, from where to be exact? Off of one of the small hex screws along the dash light circuit? I don't want to makes things worse.

Thanks/

Jan Zverina

BCA #39915

1960 Electra 4719

1963 Riviera

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Your fuse is not blowing due to lack of a ground. Running a new ground will not fix it.

Your fuse is blowing because one of the many wires lighting up the instrument panel is shorted to ground.

I recommend you investigate the light on the clock first.

There is also a light on the ignition switch (to help you see where to insert the key in the dark). I'd bet 90% of first-gen Riv owners don't know about this. Buick has it setup with the instrument panel lights. That wire could be shorted to ground. I would check it second.

After that, you need to trace out the wires into and out of the headlight switch to find where the insulation is cut through aganst a sharp metal edge and shorting out.

See if the fuse blows with the headlight switch disconnected form the wiring harness. If it does, the short is before the headlight switch. If not, then the short is after the headlight switch.

Good luck. This is why we have fuses. Otherwise you would have an electrical fire.

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My 65 was plagued by strange electrical anomalies due to previous owners attempts to bypass, rewire, & add accessories. I have been able to sort most of them out and return things to normal for the most part, thanks to the help of a neighbor who is actually smarter than I is. Issues with instrument & courtesy lights mostly disappeared with the installation of a new headlight switch, except for one…the rheostat does not dim or raise the instrument lights. (Probably something to do with the place of manufacture, it not being NOS) Oh well, can't have everything! One thing everyone should have though is a laminated color coded electrical schematic from www.ClassicCarWiring.com. It has not only proved helpful but is a thing of beauty & fun to have. I sit & stare at it like a chimp looking at fire for the 1st time. But even a chimp can't help making this observation….who in hell designed this electrical system !!!

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Your fuse is not blowing due to lack of a ground. Running a new ground will not fix it.

Your fuse is blowing because one of the many wires lighting up the instrument panel is shorted to ground.

I recommend you investigate the light on the clock first.

There is also a light on the ignition switch (to help you see where to insert the key in the dark). I'd bet 90% of first-gen Riv owners don't know about this. Buick has it setup with the instrument panel lights. That wire could be shorted to ground. I would check it second.

After that, you need to trace out the wires into and out of the headlight switch to find where the insulation is cut through aganst a sharp metal edge and shorting out.

See if the fuse blows with the headlight switch disconnected form the wiring harness. If it does, the short is before the headlight switch. If not, then the short is after the headlight switch.

Good luck. This is why we have fuses. Otherwise you would have an electrical fire.

Thanks for the clues, Jim (I love ROA!)

Just to be clear since I'm not very familiar with printed circuits, when you say "investigate the clock" do you simply mean take out the bulb and/or disconnect the entire clock and then see if the fuses doesn't blow? I'll try and get the IP schematic but can you tell me which wire on the ignition switch I'd disconnect or am I looking for a wire there that could be pinched/grounded like following the wires from the headlight switch?

Thanks!

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Thanks for the clues, Jim (I love ROA!)

Just to be clear since I'm not very familiar with printed circuits, when you say "investigate the clock" do you simply mean take out the bulb and/or disconnect the entire clock and then see if the fuses doesn't blow? I'll try and get the IP schematic but can you tell me which wire on the ignition switch I'd disconnect or am I looking for a wire there that could be pinched/grounded like following the wires from the headlight switch?

Thanks!

The printed circuit is only around the speedometer and instruments section of the dash. Look in the shop manual and you will see it. I don't expect it to be the source of the short (but you never know).

Remove the clock from the dash (turn counter-clockwise). A light plugs into the back of it that is on the dash lights circuit. Make sure there is no exposed or pinched wire there. If that light was left hanging loose it could be touching metal and grounding out.

To get to the light on the back of the ignition switch, remove the access panel underneath, next to the steering column. See shop manual. You can reach in and pull the light bulb holder loose, if it is not loose already. Same deal there, you don't want any exposed part to be touching metal and shorting out. This is different from all the wires going into the back of the ignition switch.

Same with the headlight switch. Look for any pinched or worn through insulation on any of the wires.

Hope that helps.

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