Hello everyone. My turn signals and hazard lights do work but all the other lights on the dash dont. could it be my headlight switch? My fuel gauge doesnt work either could that be related? I have a new sending unit and it has a good ground. I tested the harness under the dash. The female side had power, only on one wire. I think it was the second wire on the right side. I think it was a tan color. I was told the fuel gauge wire is brown. I seen a wire that was darker than the tan wire, could be brown. But it didnt have power. I tested these wires with the ignition key turned on. Can anyone give me some pointers on my dash lights and my sending unit please

 

Had a similar problem with my 67. I had to bend the little tabs on the dash bulb holders so they make a stronger contact. Also my bulbs tested good but would not light. Cleaned the little wires on the bulbs so they made better contact with the socket and that fixed the problem. i also put a repro tank sender in but I dont think its working. Have not even looked at that yet.

 

Take a good look at your circuit board.A loose pin and you will have trouble.I have about 15 Circuit Boards 10 in perfect shape.And it seems like the Pin at the 6 Oclock position is always shot due to the way we try to wiggle it loose.Take a look.
Let me know if I can help.
Ron

 

I just have to ask, did you rotate the headlight **** counter clockwise to the full bright position? If so, you can jumper the rheostat and see if they come on.

 

Wow, wouldn't that be trick if it was just a turned rheostat??? I like this suggestion. Too often overlooked.

ALSO, Check the fuse block for 'Inst LPS' fuse. 4 amp? Is it good?

I doubt very much that lighting on the dash has anything to do with the gas gage not working though. You might want to check the fuse block for the 'gauges' fuse. 10amp? before you start looking for faulty sender fuel tank sender.

 

Thank you everyone for the qutck responses. Allan R, all fuses are good, and get power. Oldcutlass If I turn the switch all the way clockwise and the lights should come on, they dont come on when I turn it. rroth01,Im going to check the pin at the 6 o'clock position on the circut board. Do you have any suggestions on how to check? The only thing I can think of doing is chech the wire that goes to it for power. Im going to do that today

 

Allan R, since my fuses are good, how would I test for a faulty sending unit?

 

I would start with one of the Darker Liquors.Vodka and Gin just dont cut it.Great for the summer months .But nice Bourbon or a decent Scotch even Rum.. always popular around the Holidays..These electrical things can drive you to drink..my opinion get a head start.Let me check one of my circuit boards and an old wiring harness .Maybe I can get you an idea of what pin to check in what order to give you better direction.

 

You need to remove the orange wire coming off of the sending unit and ground the side coming from the gauge. You can often find this wire in the rear of the car near the license plate, perhaps gotten at by looking around the trunk latch area. There's usually a connector there that joins the wire coming from the gauge with the wire coming from the tank sending unit. You can also just get to the sending unit itself on the tank, which is accessible without removing the gas tank from the car. When this wire is grounded with the ignition on, the gauge should immediately peg to E. Removing the wire from ground should cause the gauge to immediately go to F or even past it.

If these things happen, the wiring from the sending unit to the gauge as well the gauge itself are in good shape. You would also want to make sure the other wire coming from the sending unit, the black one, is properly grounded. Even if it's attached to the frame where it should be, if the connection is corroded and not making good electrical contact, then the gauge would not work properly.

If these tests check out ok, then the next place to look is the sending unit. On the '67 Cutlasses, the sending unit/fuel pick-up can be removed without removing the gas tank. It's on the forward face of the tank. You'll have to drain the tank below the level of the sending unit, run the car until the level in the tank is low, or siphon enough fuel out to get the level low enough.

The sending unit is held in place with a retaining ring ("lock ring") which you have to rotate to loosen. If there is enough crud and grime on it after all these years, it may require a little coaxing. I loosened mine by gently tapping the tabs with a hammer and a flat-blade screwdriver.

Note that two different tank units were used on the Cutlasses. 330-cubic inch engines used a single-line fuel pickup, while tank units on 400-cubic inch engine cars had a second, fuel return line.

I don't know if new sending units are available for your car. I don't see any at rockauto.com, but others may know of a vendor.

If you can't find one specifically for your car, you might find that something from another GM make or perhaps a later-year Olds might work. In my case, sending units are not made for my '67 Delta 88, but I found that one that fits a '72 Buick, which are made new, was a drop-in replacement.

 

Jaunty that is good information.I have a question.I did buy an aftermarket Sending unit.Not real pleased with it .Did install it.Instead of a sock type of filter ,it had a hard cylindrical filter.It may not have fit into the baffle location properly.My gauge registers just under 1/2 of a tank all the time .I do keep it full due to this problem . I do get movement out of my gauge going towards empty.But it wont go above that 1/2 mark.Is ther a way to calibrate the cheap after market Sending units or could that float be hung up.Like I said I am getting some movement.This question comes up so so often.And your sugestion makes sense .I would like your opinion.Ron Roth

 

It sounds like it's hanging up. There is no way I'm aware of to calibrate any sending unit. They're very simple electrically. Just a variable, 0-90 Ohm resistor. There's no adjusting screw or anything like that.

If I were you, I would try to get a sending unit specifically made for your car. Barring that, I would try to do what I did and get one from a reputable source that might function as a drop-in replacement. This might take a little research on your part, and you'll probably end up calling some of the vendors. But I have to believe that out there somewhere is a sending unit that will work for you.

 

Thanks Jaunty.This subject comes up all the time.No Gas Guage movement in the 66 /67
I restore IPs and many times it is the circuit board.Many times it is not. But due to the little bit of motion I have I thought may be my problem.No more products from China.Time to call my Buddy Stevie Obrien at Fusick.Thanks Ron