1977 New Yorker Gauge Cluster Problems

[77newyorker440]

Good Afternoon, thanks for all of the help with the exhaust thread that I posted yesterday, I had a few questions about some gauge cluster problems I have had with my 1977 Chrysler New Yorker Brougham with the 440.

First of all, the ammeter (alternator gauge) in my car has never moved since I bought the car, not during stat-ups, when its in accessory mode, nor when it is running. It seems to be stuck right next to the line in the middle, slightly on the charging side. Attached below is a picture. I also saw a thread earlier about the ammeter having problems if the alternator shorted out. That could have possibly happened, since when I purchased the car, the alternator voltage regulator on the passenger side fender had all the protective glue melt out, meaning that at some point it got extremely hot, possibly causing issues. So far, I have replaced the alternator (100 amp dual channel), voltage regulator, alternator ground cable, and battery ground cable. This has caused no change in the ammeter.

Second of all, the day I bought the car, the clock worked (June 24, 2020) and I took the battery out one day to put a new one in, and the clock has not moved ever since.

Third, the gauge cluster light switch appears to be broken, since when you turn the headlight switch to light the gauge cluster, it flickers at one point and is dark for the rest of the positions you can turn the headlight switch to. Bad Switch?

If you all have any questions, concerns, or suggestions, please add them below.
Thanks, 77newyorker440

 

[Davea Lux]

Run a voltage check on the battery, you should be getting about 13.4 volts with the engine running, if so the charging circuit is working. Be sure that the voltage regulator is well grounded as it will not function without a good ground. If the battery stays charged when the vehicle is driven, that is another good indication your charging system is functioning. I am guessing that the ammeter might have a stuck needle from corrosion or there is a bad connection to it. The have also been known to go 'open' so that there is no completed circuit to register charge. If you can get at the back of the unit a voltmeter can be used to determine if the unit has power to it, if not the wiring is bad someplace.

Check the fuse to the clock, it may have just died from old age. Flickering panel lights is usually caused by a bad rheostat, either in the light switch or a thumb wheel on the dash. If your car has the rheostat on the light switch, it is usually simplest to replace the light switch. Most Mopars C-bodies of that era have a thumb wheel, and those have to be rebuilt as new units are usually not available. There are rebuilt ones on E-Bay. Sometimes the rheostat just needs to be cleaned, so remove it and try that first.

Dave

 

[CBODY67]

The older "dial" clocks had a set of contact points in them, similar to ignition points, whose contract surfaces would degrade/corrode over time. Taking the back off and cleaning the points sometimes made things work again. Not sure about the Chrysler Chronometers, though, but might be similar? With a stepper motor rather than a normal motor running the moveement?

Just some thoughts,
CBODY67

 

[Mr C]

Good advice here regarding the charging system and rheostat...as an aside, the goo from the voltage regulator was not necessarily from an overheat condition. It's well known that a batch of regulators had sealant on them that was faulty and they would ooze out causing a mess. The regulator would still work but you'd have a mess on the firewall or inner fender depending on car.

I find Chronometers like to be lubricated from time to time. Pop the top cover off and you'll see the gears. A little 3 n 1 oil helps. It could be that it died too...I presume you checked the fuses.