Multiple Electric Gauge issues

[mrsnicks]

Hey guys, 1971 Dodge Charger, standard gauges here. I'm going to list all the things I have going on to see if any are related.

1. Parking lights work, but not headlights. I'm pretty sure I just need a new headlight switch.
2. Turn signals work externally, but no cluster lights and no fender mounted lights. Same with hazards.
3. Dome light works but no cluster illumination when lights are on.
4. Nada on the AM radio. No power, no illumination. (I haven't checked the wiring on the back yet).
5. Fuel gauge. stays on E. I have put in a new sending unit, have the ground clip and installed additional alligator ground clips. I have not tested continuity on the wire to it.
6. Using oil pressure light. Light NEVER comes on. When key is in run and engine not running, etc... New sending unit and wire is on it.
7. Temp gauge. Most of the time it reads straight up and down (100 degree days here) but sometimes is waves back and forth. Not jerky pegging back and forth just a slow glide back and forth over a couple seconds. New t-stat, and no air in the system.
8. Ameter. Using stock setup. Most of the time when driving it shows just on the + side of the horizontal bar, but sometimes it goes crazy and pegs out on the +and- side back and forth before returning to a stable reading.

Let's hear what you've got.

Patrick

 

[Badvert65]

OOF...Where to start....

 

[383man]

Check you eng and body grounds first. Ron

 

[mrsnicks]

Check you eng and body grounds first. Ron

Negative cable connected to engine block and firewall. I don't think there's another engine ground.

 

[mrsnicks]

I just received a 74 rallye cluster today with wiring on the back. Instead of troubleshooting the original I'll just wire up the rallye cluster and go from there. Looking for a 14 pin connector to splice into my wiring harness so I can remove the cluster when necessary. Don't want to crimp/solder the 2 parts together.

Anyone have a 14 pin connector to recommend?

Patrick

 

[nm9stheham]

The ammeter guage behavior is of great concern; it may indicate a partial/occasional short. If it becomes a hard short, it may burn your car to the ground. While you are in the dash, you need to examine/unwrap the entire harness and look for shorts. Look for burned/melted/discolored insulation to the ignition switch, headlight switch the friewall connectors, and the fuse block. With the age of the car, this should be done anyway.

The other reason for the ammeter behavior is that the alternator is suddenly going to full, unregulated charge and then back to normal charge. That can cause the ammeter to swing hard towards + for a moment. This can be caused by shorts/opens in the alternator and the associated wiring to the VR and alternator.

Do you have a voltmeter? If not, you need to get on; they will be your friend for these cars. Also, download a schematic for your car from mymopar.com

For the fuel guage, first test the voltage on the lead to the fuel sender with the ignition switch in run. It should read around 5 volts; it may jump up and down some, but it should average at 5v. There is a 'voltage limiter' in the dash that sends an average of 5v to the fuel sender and the temp sender (and oil pressure sender if you have one). If you are replacing the cluster, this should fix the voltage limiter as it is in the cluster.

 

[mrsnicks]

UPDATE after installing Rallye cluster.

1. All lights work after installing a new headlight switch and relays for good measure.
2. Turn Signals and Hazards work externally and in the cluster, but not the fender mounted.
3. Dome light works and cluster illumination.
4. Bought a new USA-230 Autosound and a working radio
5. NO Fuel gauge, Oil gauge or Temp gauge. I assume the voltage limiter and have ordered a new solid state one.
8. Ameter. Fixed the loose sheet metals screw for a good ground. Works fine.


NEW issue with the rallye cluster. Occasionally the Tach needle will "stick" in higher rpm range and takes some revvving to get it to come back down. Is this a lubrication issue? Tach gauge issue?

Thanks.