Temp gauge not working

-
4spd340Swinger

4spd340Swinger

Well-Known Member
Joined
Mar 29, 2019
Messages
487
Reaction score
1,107
Location
Cincinnati, OH
I have a standard dash in my 1969 Dart. The temp gauge has never worked since I have owned the car. Replaced the sending unit and I have proved the wire is good from the sender to the bulkhead. The fuel gauge works (only goes to 3/4 when full). Any suggestions where to start? If I remove the gauge cluster???
 
If you short the wire at the sender does the guage move? Don't do this for more than a second or two. You just want to see if it the guage moves.

Could be sender, could be pins on guage cir board, could be guage
 
Both gauges, temp and fuel, and all three (oil) are supplied by the same power source, IE the IVR various names, intrument voltage limiter.

The electrical path is sender.....sender connector.........bulkhead connector.........to dash cluster harness connector.......board trace to the gauge stud/ nut..........through gauge unit........back out gauge stud/ nut and board trace..........to IVR.

Generally "the troubles" are

Bad sender, bad sender wire connector, bad terminals in the bulkhead connector, bad connection at the harness connector, bad connection at the PC board connector pin--to board trace-------bad/ burrned out trace, bad connection(s) at the gauge stud / nuts, bad gauge unit, and broken / burned board trace to the IVR.

Pull the bulkhead connector apart and check "that far" and if not................

Likely time to drop the column and pull the cluster
 
The next step for me would be to find the other end of the sender wire at the dash or maybe just the pin at the cluster. Short that pin to ground, see if the gauge moves. Some clusters have the limiters as part of the gas or temp gauge. Details on Real Time Engineering's website.
 
If it helps, temp senders wire is purple/violet from sender to inst' panels, all models.
Defective mechanical limiters can cause high readings, low readings, and wild needle swings in the gauges. Wild swing most evident in temp gauges. Case in point is 73 Valiant,, No fault seen at cold start. At normal operating temperature, a trip to store whatever, turn switch off, turn switch back on a temp gauge needle races to its max position then falls back to normal warm water position. Repeats every time a warm temp sender is powered up. Installation of solid state regulator cured the operation but... the damage was done. This temp gauge died a couple months later.
 
4spd340Swinger said:
The fuel gauge works (only goes to 3/4 when full)
Click to expand...
From OP the fuel guage works, and it is a standard dash in a 69 dart. So the IVR is operating correctly (ish) fuel guage only going to 3/4 is troubling but might be unrelated, or might be in indicator of high resistance in the cir and a clue to the temp guage issue.
 
"post" is post with nut

Right most post (T) is temp guage to sender.
Next (5V) is voltage from IVR
Next is (F) fuel guage to fuel sender
Next (5V) is voltage from IVR


You can just see the IVR on the far left, seperate unit not part of fuel gauge. Since your fuel guage works the IVR is working so it is either tsmp guage or a connection

1591294259563831067449658910454.jpg
 
You must log in or register to reply here.
-

Back
Top