68 Charger Dropped Temp and Fuel Gauge

[Dutchrebuild]

Moved my 68 charger around a couple of times recently when suddenly temp and fuel gauges dropped to nothing. Oil and alternator gauges are working fine. That they failed together makes me believe it has nothing to do with the senders. What could cause this? Thanks!

 

[BLK 68 R/T]

Alternator gauge is completely separate from the other 3. Could be a circuit board issue or a grounding issue. With the key on you could momentarily ground the wire for the temp gauge and see if the gauge needle moves. It should move towards hot side pretty quickly. Don’t ground it for very long, only a few seconds to see if the gauge needle moves.

 

[Bird 426]

The IVR regulates those 2 gauges.

 

[Texas97]

anything on whether that voltmeter issue was fixed?

 

[Billccm]

Hopefully your IVR didn't burn out the gauge. This is the best replacement

RTE limiter - rte

 

[Dutchrebuild]

So here's where I'm at...lowered the column yesterday and changed out the IVR with a known good original. Nothing changed, still no temp or gas gauges. While under dash, I took note that all wiring, circuit board , and connections look mint original. In the course of poking at things, I had the negative battery cable on and off a few times. Suddenly, the gas gauge came online, showed correctly, but fell off to empty again. I cleaned up negative battery terminal and got good gas gauge reading. Cable was kinda beat so I replaced it with a new 1 gauge negative battery cable . My fuel gauge now works fine! But temperature still not working.

 

[Dutchrebuild]

Just wandered back out to the shop...now, gas gauge back to not working. WTF

 

[Sinitro]

So here's where I'm at...lowered the column yesterday and changed out the IVR with a known good original. Nothing changed, still no temp or gas gauges. While under dash, I took note that all wiring, circuit board , and connections look mint original. In the course of poking at things, I had the negative battery cable on and off a few times. Suddenly, the gas gauge came online, showed correctly, but fell off to empty again. I cleaned up negative battery terminal and got good gas gauge reading. Cable was kinda beat so I replaced it with a new 1 gauge negative battery cable . My fuel gauge now works fine! But temperature still not working.

The IVR was fine if the gas guage was working..
Sounds like U have a cracked PCB and/or weak connections, time to pull it and check more closely..

Just my $0.02..

 

[Billccm]

Can you solder? I had to add solder to the IVR socket connections to the PCB. I also reflowed the pins for the circular connectors.

 

[Dutchrebuild]

So I had to pull the battery to move my plow truck. Got done, put battery back in car, and fuel gauge is now working again. I took a real close look at my pin connector on the CB while I was fooling with the IVR. nothing is lose or corroded...looks like new. An " alleged buddy" ran off with my multi meter so I can't even test anything. I'm not ready to start ripping the dash apart yet. I can solder if necessary

 

[440beep]

Reach behind the gauges and with, I think it’s a 3/8 socket, tighten the nuts on the two gauges. Don’t get crazy tightening, just give them a little twist and see if that fixes it.