Wiring Questions....

[flight96 14]

Boy if there is 1 thing I hate, it's wiring !!!....So here's my issue(s)...

 

 

1. I have all lights working except my signal lights...I get nothing from them...My emergency flashers work...but no signals. I checked all the fuses and all is well...Just no signals...?
   
2. Under the dash, by the light switch, there is a green wire with a red stripe. Its hot on ignition/acc. I have looked at the wiring schematics but I just have a headache now... :-) ... I am looking for a spot to wire the automatic choke to. This would work great but I gotta think it belongs to something !!!:helpsmilie:
   
3. Finally, none of my gauges work...Just the speedo. I may not have enough gas in the tank for the new sending unit, but none of the other gauges work. Now I did make my own wire harness for the gauge feed. I have ordered a correct one but it hasn't arrived yet.
   

If any one of the great minds here could help me with these I would greatly appreciate it !!

Edited August 26, 2009 by flight96

[69RestoRod 10]

Electric choke? Mine was wired off the stater solenoid by the battery. Can't remember which terminal I or S but which ever is 12V switched with key on.

[jmlay 80]

You could wire the choke directly to the alternator. Have you had the guages out of the car and disassembled?

 

Mike

[flight96 14]

Yes, I did LED's in the cluster and cleaned up the gauges and put in new plastic faces as well as cleaning all the contacts. I could understand 1 not working but all 3 ??. I took out the plug again last night to make sure all the contacts were clean and all was good.

On the signal light issue, could it be the flasher ? I know there are 2 flashers under the dash. Is one for signals and one for hazards ??

[jkskinsfan 19]

On the signal light issue, could it be the flasher ? I know there are 2 flashers under the dash. Is one for signals and one for hazards ??

 

Yes, there are two. The Hazard Flasher is on the drivers side, and the Turn Signal Flasher is on the Passenger side. They look identical, but have different Part Numbers.

[foothilltom 33]

Hey flight96, I had turn signal issues with my boy's coupe and was eventually solved by replacing the turn signal switch (embedded below the steering wheel). The switch is like Rome: all roads go through there. I was amazed to see how many wires go through that switch even though it's primarily for the turn signals. A bad one will effect a number of things (the wiring diagram will bear this out) including instrument and brake lights as I recall.

 

It's kind of a bummer to replace, but when you finally do see it, you'll understand how fragile it is.

 

Of course, it could just be the signal flasher and that's easy to swap first. In my case, the flasher was still good even in a rust-bucket like my boy's car was.

 

For what it's worth...

Tom

[Pakrat 1,043]

If it does turn out to be your signal cam under the steering wheel (which sounds likely) DO NOT buy the contact repair kit, it's a complete waste of time, money and patience, by the whole new cam.

[flight96 14]

Well I'll replace the flasher and hope it fixes the problem...But ya know the way things go...Its NEVER the easy fix. :scared:

Where is the signal switch ? Is it on the steering column or in behind the steering wheel ?

[Pakrat 1,043]

Both, it's in the column but behind the wheel so you have to pull that off first to see it. The directional lever actually screws into it as does the hazzard switch. Basically it's a big plastic horseshoe with week brass tabs on the end that complete the circuit when you move the stick, it's a pretty delicate and brittle part.

 

You can buy the whole switch as Tom mentioned earlier for like $75 but if you shop around several vendors will sell you just the cam which is usually all that breaks and that only cost like $10 and it wires in pretty easy.

 

[flight96 14]

Well I got lucky for once !! It was just a flasher. So now the signals work and all the lights work. I have decided to change the seal beams to Halogens.

So now my next detective work will be the gauges. I have checked the fuses and cleaned all the contact points on the printed circuit board. The engine gauge wire harness should be here soon, I'm really hoping that will fix it. However that doesn't explain why the gas gauge isn't working. Next time out I will put more gas in and see if it reacts. Being a new float and sending unit it may need to have a good amount of gas in the tank to get it to register.

[foothilltom 33]

Glad to hear you solved your signal light issue. It's nice to get lucky. With respect to your fuel gauge not reading...you can do some pretty simple tests to rule things out.

 

To rule out the fuel gauge (or the wiring to it) pull the connector from the tank and ground it to a good ground. With the key in ACC or RUN, your fuel gauge should go all the way to full. If it doesn't, verify your ground (you'll need a buddy to help). If it still doesn't peg, you probably have a gauge problem or poor wiring to the gauge itself.

 

If that all works, you can test your sending unit this way:

 

Set your meter to its lowest ohm setting. Disconnect the connector at the fuel tank and put your ohm-meter on the sending unit contact point (and ground the black lead somewhere good). I forget the value for a full/empty tank, but you should definitely get some small number of ohms. As the float rises, the ohm reading will get smaller. If you have 5 gal of gas handy, you can have somebody pour that in while you measure (make sure the battery is disconnected).

 

If you get no change in the reading, your sending unit is bad (probably a bogus float).

 

Good luck.

Tom

[Pakrat 1,043]

Well see, you are finally getting some of that good luck you are well overdue for, too bad it's for a cheapo part but hey you take it where you can get it.

 

Yeah, believe it or not many new sending units get shipped with bad floats, it only takes 1 pin hole. Seems most of the times the cheaper ones with a plastic float are OK and the better ones with the brass seem to leak, you can fix it easy enough if you can find the hole though.

 

Reason #142 why it's good to have a fuel tank with a drain plug! (J/K Tom):tongue_smilie:

[flight96 14]

I found this article while doing some research...It looks like this is a common issue with these clusters...Looks like I'll be pulling the dash apart...again...

[ETstang 10]

Well - I'm back in the same situation, too

I have replaced the printed circuit board, a new regulator (one of the fancy electronic ones), checked and done the ground testing on the guages, and re-marked all my connections and have checked continuity on all the threads on the circuit board.

 

When I turn on the ignition, the fuel gauge registers the actual fuel level and then goes back to E - the oil and temp gauges are not registering when I start the engine. The Ammeter (alternator) gauge is working fine.

 

This damn dash piece has been in and out of the car some 20 times - this is no fun anymore. Thinking of just replacing all the gauges with "Real" ones.

 

Any help out therre????

Thx

[foothilltom 33]

Hmmm...bummer. If you're interested in isolating one thing at a time, I'm wondering if you've just tested the fuel gauge circuit independently:

 

* Check at the sending unit for variable ohm-age

* Ground the lead to the sending unit, turn to ON and see if the gauge maintains a full reading

 

It's odd that the fuel gauge would initially read correctly then hit bottom. Are you saying it does that just with the key on ON (not running)?

 

I know you've had your cluster in and out a bunch and it sucks taking it out again, but I recall the big connector has all those fragile contact points that can be easily damaged if you don't put the connector in just so. If you isolate the one that is for the sending unit, you could put your meter on that and see if it behaves the same way you describe when everything is connected. Unfortunately, I can't come up with a good explanation why that would happen, but it would certainly eliminate your gauges as the culprit.

 

I'll scan my wiring diagram later tonight and see what else might make sense. (Ok, I did it now). All roads go through that damn connector. Since your printed circuit board is new, I would start to suspect the connector to it or improperly grounded instruments (but you said you checked that).

 

Damn, I typed a lot and probably didn't help a lick.

Tom

[ETstang 10]

Tom:

Yes - when you turn on the Ignition switch - the fuel gauge goes to it's level (3/4's at the moment) and then just slides back to E

Nothing going on with the oil or temp at that time.

Then I start the car - fuel stays at E and no reading of oil pressure or temp - both needles are buried to the left.

Wondering if I have a bad (new) Constant Regulator - anyway to check ?

 

I have a (variable) 12V power supply instrument so I can check anything with 12v applied to it - if that is a means ???

Thx

Dick

The Alt. gauge works fine.

[foothilltom 33]

Hey Dick, this is a puzzler. For what it's worth, there are 4 things in play here:

 

1. Sending Unit

2. Voltage Regulator

3. Fuel Gauge (bi-metal strip more accurately)

4. Ignition Switch

 

You've seen the tests for the sending unit and based on your symptoms, it sure sounds like the sending unit is at least initially giving a reading. I would still be keen to fully test the unit for variable resistance, but that's possibly overkill here.

 

The Voltage Regulator is definitely in the fuel-gauge-sending-unit circuit. It's a pretty cheap part to replace and I don't know of a way to test them (I'm sure there is). You say it's new so that would tend to throw me off that scent. Still, I'd double check the connector/wiring to the regulator -- make sure everything is where it ought to be.

 

The gauge itself could be bad. There's a bi-metal strip inside that essentially moves the needled as the strip warms up or cools down depending on the amount of resistance in the circuit. It's possible the strip isn't able to hold the heat after the initial read and "cools off" to empty. You could check this theory by grounding the connector to the sending unit to the body of the car, turn the ignition to ON and watching the needle. If the needle stays pegged to FULL, the bi-metal strip is probably OK.

 

Lastly, and this is a stretch, the ignition switch governs the whole circuit. Based on your description, it's almost like the ignition switch completes the circuit just for a fraction of a second, then the circuit is open again. I would go this direction only if the above 3 don't pan out.

 

I hope this helps.

Tom

[flight96 14]

For a system that seems so simple it sure is a pain in the a$$ !!:scared:...

 

When you say to ground the connection from the sending unit for the gas gauge, are you saying to just unplug the lead wire from the sending unit, then find an area on the body and touch that wire to the body while the key in in the on position ?

Also, in the pic below of the back of the gauge, where would the cardboard have been. Obviously, after 40 years most, if not all, that cardboard is gone. By the look of the pic, both terminals have to be in some sort of contact with the metal case !!?? Am I missing something here ?:helpsmilie:

[foothilltom 33]

Hey Dick, I don't have my dash cluster out (thank god!), so I can't really comment on your 2nd question, but I'm pretty sure those are mounting bolts and not electric contacts for the gas gauge.

 

But to your first question, YES, simply unplug the connector to the sending unit and ground it the body of the car (a clean metal connection). You will probably need to roll back the rubber cap unless you have a jumper wire with alligator clips (always a good idea!). Hold that in place while somebody turns the key to ON. Observe the needle. Since there is no resistance in the circuit (you've eliminated the sending unit altogether in this case), the needle should peg FULL and STAY.

 

If the needle returns to empty (as you've described), you can safely eliminate your sending unit from the equation and go from there.

 

And yes, this is a bummer...but think of it like a good mystery. :)

 

Tom

[flight96 14]

Thanks...

Tonight I will test my patients and start hunting down the issues....simplest to hardest I think should be the course... With a slightly chilled alcoholic beverage lying in wait....