66 Charger Electrical

[hassyfoto]

OK,
I need some expert advise on the gauge cluster in the car. The background: the entire gauge cluster has been professionally rebuilt. The power supply has been rebuilt and the electroluminescent was repaired and lights up beautifully. The entire wire harness was replaced ( the original had been cut up so bad it was not usable). All the sensors have been replaced new ( 2x) to rule out the sensors as the problems.

The issue: the gas gauge works and that's it. NO other gauges will work. I have 2x, 3x, 4x checked the connections, I checked to make sure the wire harness ground wire(s) are hooked up and the contact(s) are clean. Sanded to bear metal & the wire harness is new.

Suggestions?????

 

[dpstark2]

First of all, get a test lamp or voltmeter and check the leads in the engine bay. Disconnect the oil pressure sender and temperature sender, attach the test lamp, and ground it to a good ground. The test lamp should flash on and off when the car is in "run." If it does not flash, you have no signal getting to the senders. Check your bulkhead connectors at this point. Alternatively, have a buddy temporarily short the leads for the senders to a good ground and watch your gauge begin to climb. Do this briefly only. If this works, you have a signal to your sending units and the problem is elsewhere. If neither of these produce signals (test lamp or shorting), you may have a lack of ground in the individual gauge pods in your cluster. The metal housings of these do ground. However, this unlikely since your EL is working.

Another (far fetched) possibility is that you have oil and temp sensors hooked up wrong at the gauges. The line feeding power to them comes from the fuel gauge, and splits to both gauges. Each gauge then has a direct line to its sending unit. To test this, disconnect both gauges completely at their posts in the back. Use the test lamp (ONLY A TEST LAMP - DO NOT SHORT THINGS HERE) and check that the split line that supplies power does indeed have the voltage limiter signal (lamp flashes). If you get that far and it's good, hook up that line to the gauges, but leave the sending unit lines disconnected. Use the test lamp at the other post on the gauges to see if you get the signal there. No signal = bad gauge, professionally done or not.

Try those, and let us know how it goes.

 

[A383Wing]

on the back of the dash, for the oil & water gauges, there will be 2 wires with red terminal ends and 2 wires with black terminal ends, the red ones go to the oil (bottom) gauge. It does not matter which red goes to which terminal

Bryan

 

[hassyfoto]

Thank You,

I will try the following suggestions memorial weekend when I have plenty of time to play.

 

[shorty64]

If needed, you can find a wiring schematic on mymopar.com, plus troubleshooting info in the Resource Guide on the 66-67charger.com site.

Best of luck in your endeavors.

 

[gibber]

I rebuild these 66/67 Charger EL instrument clusters as a side business. If the fuel gauge works, the 5V limiter supplying power to it works. It could be an issue with the brown wire sending power from the center post on the fuel gauge to the two brown wires for the oil pressure and temp. Easy way to see if the gauges themselves are getting power is to have the ignition ON, disconnect the sending wire from the oil press and temp gauges and ground them (only for a short time). Have someone look at the gauge and see if it moves towards HOT or High with the sending wire grounded for that instrument. I just noticed DP offered the same advice.....If they move, its an issue with the sending unit(s) or the connectivity from the sender to the dash wiring harness. If they don't move, could be an issue with the brown wire from the fuel gauge to the oil and temp gauges (dash harness issue). Good luck and feel free to contact me if you need more help...

Mark
www.thegaugedoc.com

 

[hassyfoto]

Mark,

I have completed all the steps as listed. Still a no-go on the oil/temp gauges. Advice requested.
Kirby

 

[gibber]

So you have grounded the oil pressure gauge and temp gauges and they wont move? I'd run a jumper wire from the 5V post on the fuel gauge to the oil pressure gauge and then ground the sending wire, do the same for the temp gauge and let me know what you find...

Mark

 

[hassyfoto]

Mark,

After numerous hours of playing with the dash and replacing both sending units 3 times. I did get the oil gauge working, but no go on the Temp. I have run a jumper wire from the temp to a ground and the gauge with peg to the high side. This is almost a year playing with this and I still don't have a working tach or water temp working. I have checked the grounds, replaced the sending units and grounded the gauge.
Next step

 

[A383Wing]

possible wrong sender on temp if needle pegs when grounding the wire to sender