Courtesy Light staying on/ Dash lights not working

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Steve Clason

Steve Clason

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Well, I'm still trying to run down this issue and wonder if it is the ignition switch. Here's the story. During restoration I put a new wiring harness on the car. I had everything working lights, courtesy lights, dash lights. But then, the dash lights started blowing the fuse. Thought it must be something jostled under the dash. But then, the courtesy lights no longer shut off.

So thought it was door switches, changed them no change.
Must be the headlight switch, Changed that, no change.

So diving under the dash Saturday but in the back of my mind I'm wondering if the ignition switch (which is original) is the problem.

1966 Barracuda


Any ideas or other things to check. The current plan is running one wire down at a time but I'm not positive how to check the ignition switch.

Help!!!
 
I cannot imagine what in the ignition switch, is common to either of these symptoms.
All dome lights are controlled by the ground leg of the circuit. This can be a problem as simple as a bad bulb or an incorrect bulb and if all (if more than one) dome / courtesy is on, it could be any of them, although it is more likely that the problem bulb/ socket is not working.

Dash lights. No fun. There is a "bunch" of lamps depending on the car model, here is how it works:

The light switch has TWO power supplies, one for ONLY the headlights

The second feed comes off the tail lamp (fuse if there is one) and feeds the circuits in the switch for park/ tail/ and to the dash dimmer. Through the dimmer control, out of tan wire, to the fuse box and through the INST fuse, and then off to all the dimmer controlled dash lighting on ORANGE wiring. So whatever lamps in the cluster, the radio, the shift quadrant, and the ash tray if used. There might be another 1 or 2. You are simply going to have to chase them all down. You could separate the radio connector, but if that, the short could be closer to the dimmer. You could separate the cluster connector, but again, same deal. Visually examine wiring and harness for a "pinch" AND WIGGLE TEST

There are devices "short finder" You put them in place of the fuse and they cycle like a turn flasher. THIS MAY DAMAGE THE dimmer control, so if you do this, wire the test device to the ORANGE wire side of the fuse clip and wire the power side of the test device to power elsewhere.

KD Gearwrench Tools 2524D Short Circuit DetectorKD Gearwrench To
 
Twist the headlite knob back and forth a few times.
Courtesy lites are triggered off the headlite switch rheostat as is dash lite brightness .
 
inertia said:
Twist the headlite knob back and forth a few times.
Courtesy lites are triggered off the headlite switch rheostat as is dash lite brightness .
Click to expand...
Geez I was gonna mention that and completely forgot!!!
 
Thanks guys, I will do and examine all the items you mentioned. Did the rheostat, so one thing done.

Deep dive tomorrow!
 
So deep dive shows the entire car is hot. Hooked ohmmeter to positive cable when unhooked from battery. Ground to battery also unhooked.

Any metal gives continuity engine, dashboard etc. ran down dash wiring and the other under dash. Catching my breath since it’s 86 with dew point of 78.

other than keep chasing individual wires any ideas
 
Does the 66 have courtesy lights? Like the 67-9 fastbacks ? Courtesy/pillar lamp housing shorting out?
 
I just redid my entire rear harness and wrapping up dash harness. Our 67 courtesy bulb holders are plastic and they get BRITTLE, crack etc. Those bulbs are extremely close to metal and could short out.
Find the LED equivalent of that bulb and replace them. Less heat is a good thing.
Steve Clason said:
Yes it does. Pulled one no change. Going to pull other next
Click to expand...
 
4spdragtop said:
I just redid my entire rear harness and wrapping up dash harness. Our 67 courtesy bulb holders are plastic and they get BRITTLE, crack etc. Those bulbs are extremely close to metal and could short out.
Find the LED equivalent of that bulb and replace them. Less heat is a good thing.
Click to expand...
Second courtesy light pulled no change.
 
So I've pulled the dash, disconnected the light switch, ignition switch, so I'm thinking maybe bulkhead? This did have a complete wiring harness within the last three years. My wife reminded me it seemed to start having problems after a trailer ride. Things I've not checked include the dimmer switch. What else should I check. With all these things unhooked still get positive continuity with ohmmeter running from positive cable to anywhere on the metal of the car.

So how to test bulkhead, fuse block, (Both look fine) Have had prior issues with fuseable link but car starts and runs fine.

(again both battery cables are off the battery and not touching metal)

Love some ideas and how to. Will be going back to review the replies again and try some more items.
 
Dimmer switch(plastic plug) is notorious for shitty shape, all the ones I've seen anyway. Damp floor and dimmer switch, is a recipe for s**t stew. I redid my entire dash harness and went thru about 5 harnesses and everyone had the dimmer switch plug melted.
Electrical is voodoo to me, sorry I ain't much help, other than chk bulkhead connectors and any and ALL connectors.
What you could do is pull 1 fuse at a time and check for the fault after each fuse pull? That might lead u to the problem?
 
4spdragtop said:
Dimmer switch(plastic plug) is notorious for shitty shape, all the ones I've seen anyway. Damp floor and dimmer switch, is a recipe for s**t stew. I redid my entire dash harness and went thru about 5 harnesses and everyone had the dimmer switch plug melted.
Electrical is voodoo to me, sorry I ain't much help, other than chk bulkhead connectors and any and ALL connectors.
What you could do is pull 1 fuse at a time and check for the fault after each fuse pull? That might lead u to the problem?
Click to expand...

Thanks I'll check those things you suggested
 
Open ground somewhere, I had it where my map light came on when I pushed the cigar lighter in. On another car, dual bulb tail lights (two bulbs per side), when I used the turn indicator the bulbs would blink alternately (inboard/outboard, same side of the car).

Something you worked on recently needs to be taken apart and put back together. This also happens on newly painted cars as sometimes the screws do not cut the paint enough.


Alan
 
Finally got it. No problems on my last outing. Wires wore bare going across the header between the pillar post sockets. There was no grommet where the wire went through the header frame. Found a similar problem where the wires to the front bumper turn signal. So thanks all for the variety of things that led me to a successful conclusion
 
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