Kevin2

I am working on a 66 cutlass 330 and I am having trouble with a couple things. First someone before me changed the wiring for the horn circuit and now it doesn't work. I was hoping to change it back to the original circuit but I can't figure out how it should go. Second the fuel gauge doesn't work and I have no idea why. I am pretty good with electronics and I have access to someone who is even better so be as technical as you want.

66luvr

On the fuel gauge. There are 2 wires back at the tank, one comes to the front/dash gauge. The other goes to ground. First thing I would do is take loose the small bolt with a 1/4" head that makes the ground and clean it to make sure the ground is good and see if that helps. That fixed mine. If that doesn't work, the next thing I would do is put someone inside the car while I was under it, with the key on, take the wire that goes to the gauge loose from the sending unit and ground it, making sure you use a good ground, if the gauge goes to full the dash gauge is good and the tank sending unit is likely bad. If the gauge doesn't move it could be the in dash gauge is bad and would need to be investigated further. The ground might be bad in the dash, wiring could be bad in some place, what I am saying here is I couldn't just say the dash gauge is bad and it would need to be checked further.
The horn circut is shown in the picture. There are two wires in the horn plug at the horn relay/junction block. The black goes, ultimately, to the horn button in the steering column. The green one goes to the horns. You can check the horns by giving the green wire 12 volts. You can check the relay by giving the black wire a definite good ground. That should give enough info to figure it out.

Kevin2

I had already cleaned the ground when I was under the car doing something else but I never tested it, and the fuel gauge is currently pointing at full even though there is only a few gallons in the tank. Could this mean the needle is stuck? Also do you have any pictures of the connections at the horn itself and connections at the switch?

66luvr

On the fuel gauge, I'm now stumped, hopefully someone else will post some answers.
On the horn, it doesn't wire to the switch. The horn works with the switch in the off or on position. The entire horn circut is 2 wires. The juice originates at the junction block which is a combo with the horn relay, the green wire carries the 12v to the horn when the black wire is grounded. Grounding the black wire triggers the relay to send the juice to the horn. The black wire grounds through the steering column, through the turn signal cancelling cam, and to the horn button, a little more difficult to get pictures. Would also need to know if you have a tilt column or a non=tilt, they are different in the wiring for all the column stuff. Before I start trying to take pictures of a bunch more stuff I would like a report on what is going on with your car, like is there wiring present where the existing picture shows it? Did you check the horns and relay like I described? No reason to dig deeper until we know what is going on right now. Maybe you can post a picture of what is under your hood for wiring in the area of the pic I posted.

BILL DEMMER

grounding the gauge line will send the needle to empty, an open circuit will read full or above.


bill

Kevin2

I forgot to mention earlier that the car belongs to a friend so it isn't readily available. It is a non tilt column. I believe all of the wiring is still there, but without knowing what was there originally I couldn't tell for sure. At the junction block/horn relay the black connector with two leads coming out is disconected and has a jumper connecting the two leads, so it is basically acting as a single wire. At the horn there are two connectors but only one is connected to the horn and the other is just hanging there. I only have a few pictures right now but I will post them in the morning, if you need to see more pictures just let me know and i will get them as soon as I can. I probably won't be working on the car again till tuesday (just an FYI).

Kevin2

I'm not exactly sure how the gauge works. When I removed the gauge cluster cover and removed the fuel gauge there was just three metal posts that the gauge screwed into. So I dont know if I need to remove the whole dash to get to the rest of the wiring or if something is missing. If you have any knowledge about that it would really help in testing it and eventually fixing it.

Kevin2

Here are the pictures i have so far of the horn.

Kevin2

Sorry some of the pictures are a little blurry but this is all I have right now.

BILL DEMMER

join www.wildaboutcarsonline.com (it's free). then go here: http://wildaboutcarsonline.com/membe...ctions_12A.pdf <<<full wiring diagram

there, you will find almost everything you'll ever want to know about the '66 olds'


bill

Kevin2

Thanks I will check it out hopefully I can get everything wired correctly.

Run to Rund

The 66 half moon connector should have wires in this order:
green, yellow, dark blue, white, light blue, purple, black, empty.
Here is what they are for:
rt turn/tail; l turn/tail; rt park/turn; stop; l park/turn; flasher (turn signal); horn.
Thus the black lead for the horn is on the end, with an empty hole beyond it at the very end of the connector.
It looks like the horn relay failed so the previous owner jumpered the two wires that attach to the relay, and proceeded to do other things that should be undone also.

RandyS

I think the same guy that worked on your car worked on mine...........

Kevin2

I managed to rewire the horn circuit to the correct way. It turned out that whoever messed with the wiring also put in a new horn which is what really confused me originally because the connectors on the green wire did't fit. Now I am in the middle of repairing the relay because most of the ones I found online were too expensive.

Kevin2

I finally got to working on the fuel gauge and I found that the sending unit was faulty. So I installed a new one that I tested before installing. But for some reason the gauge still reads full even with the tank empty. I'm thinking there might be an open in the circuit but I've gone over all the wiring already and I haven't found anything. Does anyone have an idea of what the problem could be?

RandyS

Were you able to check for continuity of the wire with a DVM (ohm meter)? Wires have been known to break inside the insulation and if that happens, you can't tell it by looking at it.

Kevin2

I was able to test it, but I'm thinking I might have left something disconnected either that or the hot wire going to the sending unit doesn't have a good connection. I'm going to check everything again today hopefully I can find the problem.

JayBrown

I am not much of an electronic kind of guy but sure I had some little knowledge about wirings etc. I have a problem with my fuel gauge, I'm actually far from a gas station and my fuel gauge says that my fuel tank is half full when it really is empty got my car pulled. Well the reasons would lie to loose, dirty or corrosion. I tried replacing parts (bought online carparts) since even after troubleshooting it still reads as empty.

davidmorrison

On my '67: contact unit in steering column seems to be missing a keeper that puts tension on the spring and keeps it in contact inside the turn signal assembly. Any know about this??? Replace for the keeper? Is it integral to the spring/wires? Dave