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Discussion Starter #1
To give some background, I've been working on my 69 vette at removing the odometer and had to remove the entire dash.

So far so good. Got the odometer fixed started putting everything back together. I replaced all the bulbs and fixed a couple bulb wires.

I have, as far as I know, all the wires connected again. What I dont have connected is the tach and the speedometer cable. I also do not have the panels actually screwed in, they are just hanging.

I started to put it all together and noticed some lights in the instrument panel and the console weren't working.

Let me say what is working first.
The emergency brake light works
The brights alert light works
The hazards light work
Headlights work
Passenger floor bulb works (the larger bulb)

Interior light in the back and driver's side light don't work but they didnt work before (havent changed bulb on them yet)

What bothers me is the turn signals do not work and did before.
ALso, all grey wired bulbs in console and panel do not work. These are the basic lights that are used to light up everything.

It also appears that also my back up lights do not work. Which I noticed seemed to be related to the turn signals in some way.

I've changed the bottom two fuses in the fuse box, even though the both looked to be ok. One specially says back up lights and dir signals. The other was an oops replacement.

Can anyone help with with any suggestions I may have overlooked or common problem areas for these circuits. No atter how obvious it is. I've found the most obvious reasons for me are the ones that are normally what are wrong.

I might be missing some ground or something I forgot to connect back up.

thanks
jim

p.s. Yes I do own a assembly manual, repair manual, chiltons and an owner's manual.
 

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To give some background, I've been working on my 69 vette at removing the odometer and had to remove the entire dash.

So far so good. Got the odometer fixed started putting everything back together. I replaced all the bulbs and fixed a couple bulb wires.

I have, as far as I know, all the wires connected again. What I dont have connected is the tach and the speedometer cable. I also do not have the panels actually screwed in, they are just hanging.

I started to put it all together and noticed some lights in the instrument panel and the console weren't working.

Let me say what is working first.
The emergency brake light works
The brights alert light works
The hazards light work
Headlights work
Passenger floor bulb works (the larger bulb)

Interior light in the back and driver's side light don't work but they didnt work before (havent changed bulb on them yet)

What bothers me is the turn signals do not work and did before.
ALso, all grey wired bulbs in console and panel do not work. These are the basic lights that are used to light up everything.

It also appears that also my back up lights do not work. Which I noticed seemed to be related to the turn signals in some way.

I've changed the bottom two fuses in the fuse box, even though the both looked to be ok. One specially says back up lights and dir signals. The other was an oops replacement.

Can anyone help with with any suggestions I may have overlooked or common problem areas for these circuits. No atter how obvious it is. I've found the most obvious reasons for me are the ones that are normally what are wrong.

I might be missing some ground or something I forgot to connect back up.

thanks
jim

p.s. Yes I do own a assembly manual, repair manual, chiltons and an owner's manual.
I think you have 2 or 3 different issues here. The turn signals go through the harmonica connector on the steering column. Perhaps you knocked that loose while working, or somehow broke the turn signal switch. Not sure where the reverse light is routed but there may be a connection in the console area. The dash lights are all siamesed together so any wire getting pinched and grounded is going to take out all of them and the fuse. I have been chasing a dash light short in my 72 and haven't found it yet.

Did you check the fuses again to see if they are blown? If they are you have a short (probably a pinched wire) and if they are not you are probably not getting power to the bulbs. A voltmeter will be a big help in troubleshooting.

I think there is a gound connection on the back of the tach that provides ground for all of the dash instruments.

Speedo and tach cables should have nothing to do with these problems.

:cheers:

Rick B.
 

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At the bottom of both the tach and speedo there are grounds. If they're not plugged in lots of things won't work. Also look at the left pillar- the harness ground is above the hood release. Black wire with a ring terminal.

Double check the harmonica connector- looking at your list, several of the things you have that are not working run thru that. The reverse lights switch is either in the console (auto) or mounts on the trans.
Check too that the panel dimmer is turned up- easy to miss, and if it's turned way down the lights are really dim.
 

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Discussion Starter #4
I'll check the harmonica connector and ground you mention tonight when I get home.
Could either of these being loose explain why some of my cluster light circuits are working and some of them are now not working?
 

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You bet- if the harmonica is loose- the turn lights go thru that- and the panel ground is easy to tug on when you pull the dash aft. Maybe not hard enough to break the wire, but maybe loosen the screw that it goes to.
 

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Discussion Starter #6
Checked the ground and it seemed intact.
Is the harmonica connector that place where 10 wires come together near the steering colum into a plastic connector?
If so it seemed in good shape also.

One thing I noticed is that i have a plastic connector neer the console I have pulled out that I can not find a location for it to go.
It has 2 light blue wires that combine.
One dark blue wire and a black wire with a white line.
Here is a picture of it.



Not a great picture but hopefully enough for someone to identify for me if they can.

thanks
 

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I know you have checked but go over your ground wires again with a good meter. I have had a ground wire at the tail light cause the dash lights to not work. A gremblen in the ground wires on these things will drive you nuts.
 

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:agree:

While you have the center dash out, check the ground from the metal can on the back of it to the battery (-) negative terminal. IIRC that ground is shared with the speedo/tach.
 

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Discussion Starter #11
I know you have checked but go over your ground wires again with a good meter. I have had a ground wire at the tail light cause the dash lights to not work. A gremblen in the ground wires on these things will drive you nuts.

Ok, I will check the grounds with a meter. But I have a question, how do you go about checking a ground wire with a meter if both ends are far apart from eachother?
You do mean, check the ground wire for continuity correct?

""While you have the center dash out, check the ground from the metal can on the back of it to the battery (-) negative terminal. IIRC that ground is shared with the speedo/tach.""

When you say the battery negative terminal on the metal can, do you mean the back of the battery charge meter in the console?

thanks
 

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Meter on OHMS, touch one lead to the metal can on the back of the center cluster, and the other lead to the battery negative. If there's a break between then, as in a poor/bad ground, the meter will read what the resistance is. If it's all good, the meter will go full scale- just like touching the 2 leads together.
 

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Discussion Starter #13
Meter on OHMS, touch one lead to the metal can on the back of the center cluster, and the other lead to the battery negative. If there's a break between then, as in a poor/bad ground, the meter will read what the resistance is. If it's all good, the meter will go full scale- just like touching the 2 leads together.
I think I understand now. When you say the metal can, you mean the metal that all the meters and lights are attached to in the console. I will probably need wire to extend the lead on the ohm meter to reach the negative on the battery I assume?

Sounds like I can use this for all the other grounds? I can use it to check if the speedometer is grounded and the tachometer (general lights - gray wired) arent working there also. I can also use it to check the wire harness ground by the hood release?

thanks
 

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I think I understand now. When you say the metal can, you mean the metal that all the meters and lights are attached to in the console. I will probably need wire to extend the lead on the ohm meter to reach the negative on the battery I assume?

Sounds like I can use this for all the other grounds? I can use it to check if the speedometer is grounded and the tachometer (general lights - gray wired) arent working there also. I can also use it to check the wire harness ground by the hood release?

thanks
EXACTLY! As long as your connection to the meter lead is good, and you can check that by adding the length wire you need, touch the extended wire and the other lead and adjust the zero on the meter. Now it's calibrated for the longer leads.

And you can check every ground the same way. Touch the ground at point "A" and the battery negative.
 

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Discussion Starter #15
I made some progress already today. I took the 5A mini fuse in to work that is for the interior dash lights. I had a second person check it with a volt-ohm meter. He said it was fine (same as me).
At lunch however, I bought some new fuses. I put one in the 5a slot and the dash lights work.
I don't know why, but I am not going to complain.

On that note, I replaced for a second time the 20 amp fuse that is the 2nd from the bottom right. It is labeled back-up light and dir signals. I have always assumed this is for the back up lights and turn signals. These both still don't work but are my last items to get back functioning.

Now that I belive those are both on the same circuit. Can anyone suggest to me the ground they both might be using? The hazards work but the turn signals and backlights dont.

thanks

p.s. I do not have the lower 2 steering column bolts in currently. I assume they don't affect the grounding of the column and this circuit.
 

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The 20a fuse is the power feed, so if that fuse is good and you have power on both sides of that fuse, then I'm going to go back to a ground. The tail/turn/stop/backup lights ALL use a common ground- it's on the frame at the rear. follow the wires from the tail light housings- someplace back there a single black (probably all look black after 40 years!) will come out of the harness and go to the frame. The front turn/park lights ground to the radiator core support at the lower left front. the core support, in turn, has a jumper to the frame.

The column mount is a non issue- everything should work without it.
:cheers:
 
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