Gauge and inside light above head 1972 Cutlass S.

When I turn on lights I have headlights and taillights. I have no gauge lights.

Buzzer works when drivers door is opened, but not on passenger side. Tested white wire going to passenger side. Have 12+ volts. White wire good from where it comes out of loom just to right gauge panel and I assume good because of voltage?

The gray wire only has .97 volts and at all times when key is on.

 

The key-in-ignition buzzer is on the drivers side only to alert the driver the key is still in the ignition.

 

I believe I understand your explanation.

The buzzer only sounds and the overhead light is illuminated when driver door is opened?

The switch on passenger side only causes the overhead light to illuminate when passenger door
is opened and no buzzer will sound?

I will check power to overhead light when either or both doors are open.

 

I am only 100% about yellow and white wires. Yellow = Radio
White = doors
Remainder?

 

Checked for power at Dome Light with bulb in. Filament intact.

Zero power at one end. 12+ volts at opposite. Checked bulb itself and I believe that bulb is bad even though filament looks good. Does not even light up powered at the battery.

Hopefully new bulb will remedy Dome Light.

Still no gauge lights???

 

Will the circuit be incomplete if there is no radio? As in wires are disconnected.

Would this cause issue?

 

On dash instrument lights- rotate the headlight switch **** all the way counterclockwise (left). You should feel a stop. This is the rheostat that controls brightness of the instrument lights. Rotate the **** past the stop and you'll feel a detent. This should turn on the overhead dome light.

If rotating the headlight **** doesn't turn on the instrument lights, look in the fuse block and you should see a short fuse labeled INST LPS. With head or park lamps ON, probe both ends of the fuse with a voltmeter or 12v test light. If it's bad replace it. If it tests good, problem is on the load side of the fuse, probably the gauge printed circuits or the dashboard ground strap behind the instrument panel.

Do you have the color wiring diagrams from the 1972 Olds factory Chassis Service Manual? Because it sounds to me like you don't. That book will be the best investment you ever make for your car. Just probing random wires without understanding the car's wiring and electrical system is the way Chevy guys make electrical repairs.

 

Rheostat has stop. No luck there.

Will check fuse today.

Have a diagram. Just did not understand green with with white stripe wire. Green with white stripe wire Is in a wide plug with black wire.

Another thing that I do not understand that grey wires have approximately .95 volts with key on.
my only guess is this is from the rheostat and rheostat does not work correctly.

 

Looking at the wiring diagram I will assume that power must run through the headlight switch prior to going thru the fuse panel.
Using a voltmeter I found that when I turn on lights I get power to inst at fuse panel.
No power at wire coming into back of gauge
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Same voltage on both sides of the INST LPS fuse?

 

Yes

 

Does the power from the rheostat go through the fuse then to the lights or is the fuse first? Maybe bad rheostat? Open electrically (continuity)?

 

Im going from memory, so hopefully this is accurate.

Dash light power comes out of the headlight switch on a green wire to the dash light fuse. The power comes from the taillight circuit. No taillight power, no dash lights. It comes out of the dash light fuse as a gray wire where it splits to individual dash and console backlighting. There will be no power on either side of the dash light fuse unless the taillight are on, and the reostate is turned clockwise.

 

Have taillights, brake lights, and turn signals

 

My Assembly Manual is in black and white and doesn't have wire colors noted.
The wiring diagram is color coded, but does not show the connectors.
Does anything show both?