Testing a temperature gauge

[Kern Dog]

When I had the gauges out of the Jigsaw Charger, I tested each one by putting 12 volts to them just to see if the needles moved. They all did.
I have a 67 Dart out back with an engine swap coming and I want to get the temperature gauge working. First though, I want to see if the problem lies elsewhere.
Isn't there a test.....where you pull the wire from the sending unit, ground it and watch the gauge to see if it pegs to the high side?

[John_Kunkel]

Grounding the wire "briefly" at the sender will tell if the gauge works but not its accuracy.  As you probably know, the gauges operate at a nominal 5 volts so don't run 12 volts through them for any length of time.

[Nacho-RT74]

Yes, you can ground the sender wire and gauge should go a bit over the max reading.

Test gauges with 12 volts is REALLY dangerous. If you let them connected for more than a second they simply will burn. Better use one 1.5 volts batt, or two in series (3 volts)... or a cell phone charger (they are 5 volts, althought old Nokia ones use to be 4.5)

[Kern Dog]

I tried it on the Dart. The fuel gauge and temp gauge have been dead for awhile.
I also tried it on another car...My "Jigsaw" Charger. I only had it grounded a short time (off and on for well under 20 seconds total) and saw no reading at the gauge....but now it doesn't show a reading to the oil pressure, fuel or temp gauges. They all worked before so I must have screwed up. I guess I'll have to pull the cluster and replace the voltage limiter. I have several instrument panels from Dusters and Darts.

[Kern Dog]

I don't know what the heck happened. I went out to start the car today and this happened:









Yeah....the gauges were dead yesterday but worked fine today. Looking around the internet forums, it seems that when all three are dead (Fuel-temp-oil pressure) then the problem is usually the voltage limiter.

[69hemibeep]

Pay a little extra and get one of these. https://www.rt-eng.com/index.php/RTE_limiter.html

[will]

I think the chineseum senders stink. I have a gauge next to the sender that reads well above 50 psi but the dash gauge is not accurate.

[Kern Dog]

Just an aside to this...
My ratty 67 Dart had no movement at the temperature and fuel gauges for at least a couple years. I don't drive it much so it wasn't a priority to fix it. With the engine swap project planned, I wanted the gauges to all work.
I tried swapping gauge clusters, changing the IVRs, cleaning the wire terminals and nothing made a difference.
I had an instrument panel on the table and put power to each gauge and they did move so I knew the problem was elsewhere.
I backed off the attachment speed nuts and cleaned the circuit board contacts, I cleaned all attachment points and even went so far as to pull the bulkhead plugs, spray them with DeOxit and scrub terminals with a wire brush, then pack the plugs with dielectric grease.
Now the gauges work like they should. I credit the clean terminals with no corrosion.
Score!

[Dino]

My water pump has 2 sensors; one goes to the stock gauge, the other to the EFI ECU. The ECU reads a steady 185 when cruising while the stock gauge reads about 220. I don't like it, and I know it's easy to adjust, but I really don't want to pull the cluster again.