Instrument cluster lights 76 Cutlass
Thread Starter
mobbin in my old school
Joined: Mar 2010
Posts: 126
From: Bay Area
Instrument cluster lights 76 Cutlass
Hey guys, its been a minute. Decided to pull the cutlass out after sitting for a few years. The problem started before I parked it. Basically my instrument panel will not light up anymore. All of my dummy lights, gas guage and seatbelt lights work but not the actual light so that I can see what I'm doing in the dark. All of my exterior lights are working also. I checked the fuse and it looked fine, I replaced it anyways but no change. I read in some other threads to check the ground. From block to fire wall is fine but as far as under the dash I'm not even sure what I'm looking for. Any help would be appreciated.
Oldsdruid
Joined: Dec 2007
Posts: 10,633
From: Southside Vajenya
Had to ask. We've had a few cases on here that the car owner didn't know about the dash lights rheostat.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
Thread Starter
mobbin in my old school
Joined: Mar 2010
Posts: 126
From: Bay Area
Had to ask. We've had a few cases on here that the car owner didn't know about the dash lights rheostat.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
On another note, hoping you might know, I just found that the tong that connects to the bottom of the bulb in my reverse light is broken off. Can I repair it or would I have to find a whole new housing unit?
Thread Starter
mobbin in my old school
Joined: Mar 2010
Posts: 126
From: Bay Area
Had to ask. We've had a few cases on here that the car owner didn't know about the dash lights rheostat.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
Thread Starter
mobbin in my old school
Joined: Mar 2010
Posts: 126
From: Bay Area
Had to ask. We've had a few cases on here that the car owner didn't know about the dash lights rheostat.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in the headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
Thread Starter
mobbin in my old school
Joined: Mar 2010
Posts: 126
From: Bay Area
Had to ask. We've had a few cases on here that the car owner didn't know about the dash lights rheostat.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in t inhe headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
These clusters pull out from the front. Two, maybe three screws in each bezel and they'll pull out toward the steering wheel. You'll have to reach up behind the dash and loosen the speedo cable unless car has cruise, then you can disconnect it at regulator underhood and pull it out far enough to work.
There are pin connectors on each cluster. Before you pull the plugs, look at them closely to make sure nothing's broken and even then be really careful because these pins are known to break off the circuit boards. Then check ALL the cluster light bulbs. The gray wire in each pin connector is the lighting power feed.
If they're OK, next stop is the headlight switch. Again, the dash panel will pull out from the front; you might have to unhook the park brake cable to get it out far enough to work.
Look for a gray wire in t inhe headlight switch connector. It's dash lights power feed. Do some continuity checks from red power feed to H/L switch and the gray wire (gray should be hot in park or head position) and notice whether the rheostat coil is clean and not burnt or broken.
IMG_20150915_003527_zpsmmxuxa2m.jpg
Last edited by 76_cutty; Sep 15, 2015 at 01:31 AM.
Hookers under Hood
Joined: Nov 2013
Posts: 3,543
From: Ontario, Canada
76 Cutty, I feel your frustration and wish I could help. I haven't had any issues with the wiring on my 76 to be able to help you out. All I can say is try to test the wire as far back as possible, their may be a dead spot in the wire a some point. I will be following your thread as it will help me in the future.
Eric
Eric
Registered User
Joined: Sep 2011
Posts: 1,399
From: South Central, KY
The green wire from the headlight switch feeds 12V to the 4 amp instrument panel lamp fuse. The wire is gray on the other side of the fuse. The gray wire feeds the instrument panel lamps as rocketraider said. The black wire on the headlamp switch and instrument panel plug is the ground. The ground is just as important as the 12V.
Check for power starting at the green wire through the fuse on the gray wire up to the instrument panel plug. If power is good then check the ground.
Don W
Check for power starting at the green wire through the fuse on the gray wire up to the instrument panel plug. If power is good then check the ground.
Don W
Registered User
Joined: Sep 2011
Posts: 1,399
From: South Central, KY
So an easy step by step process would be to check for 12V at the following in the order listed.
Red wire at headlight switch
Green wire at headlight switch (with headlights on)
Check both sides of 4 amp instrument lamp fuse (with headlights on)
Check gray wire (with headlights on)
Don W
Red wire at headlight switch
Green wire at headlight switch (with headlights on)
Check both sides of 4 amp instrument lamp fuse (with headlights on)
Check gray wire (with headlights on)
Don W
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