on my 65 valiant my temp gauge is not working and could use some help. i've checked the wire for continuity from the gauge to the sending unit and all is well. i've used a jumper to ground to gauge and the needle moves, i,ve read the post about the regulator on the back of the cluster and i assume it's ok since fuel gauge is working (not sure if this is true though) i appreciate any help....thanks

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64 barracuda
64 valiant convertable
65 valiant sedan
65 signet
74 vw beetle convertable
79 E-250 4WD van
94 dodge dakota

Try disconnecting the sender and connecting a incandescent 12V test light in it's place - with the ignition on, the light ought to come on and start blinking on and off after 15 sec or so and the gauge ought to read ~1/2 scale-ish (the #s are very rough).

If that's the case, you're sender is open. If you don't get the light to come on there, I'd check the bulkhead connector next, and then work your way back to the instrument cluster. It doesn't take much corrosion to stop 12V.

everything (continuity) is good to the sending unit from the gauge. it appears i'm losing the 12v feed going into the gauge. without the 12v i believe the test light theory won't work. i know i have 12v going into the back of the cluster but it's not making it to the gauge. since one of the prongs from the regulator goes into the circuit board part of the fuel gauge feed i'm wondering if this could have something to do with the problem?

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64 barracuda
64 valiant convertable
65 valiant sedan
65 signet
74 vw beetle convertable
79 E-250 4WD van
94 dodge dakota

A DMM may buzz continuity at as high as 100ohms, while you want <1 ohm; that's why a test light is sometimes better - it draws enough current to simulate a sender.

I think I remember that the '65's had the voltage limiter inside the fuel gauge; it output pulsating 12V (averaging out to around 5V) to the other gauges (except the tach - they take 12V).

The fuel gauge's 5V output pin has a PC board trace carrying the 5V to the other gauges . If your gauge moves when you grounded the sender pin, it must be getting some power to the gauge; if you had continuity to the sender too, then the test light must work; so you are facing one or more bad, possibly intermmitent, connections - they may only work when you're pushing on them a little or have a high resistance.

The fuel gauge hass +12V in, +5V out, sender, and ground.
The temp gauge ought to have 2 pins; one for +5V, one to the sender. Touch the test light to either pin and it ought to light up; perhaps a little brighter on the +5V side, but ought to blink for both sides. If it blinks on one pin and not the other, the temp gauge is open inside and hence needs replacment or repair. If it blinks on both, it ought to read something with the lamp connected to the sender side. If it does, then it should also read the same with the test light connected at the sender location. If it works at the pin and not at the sender, your problem is between those two points.

If it doesn't light on either pin, you've got an open between the fuel sender's regulator output and the temp gauge power in. It's best to pull the dash in that case; that makes fixing it much, much easier. You can clean and if necc. resolder the connections and test the cluster before you reinstall it. You'll need +12V and ground to the fuel gauge to get the 5V to the temp gauge.

It is not uncommon for connections to oxidize abit over the years and make poor connections, even though they don't look too bad. Clean all of them while you've got easy access, and check them while wiggling too.

Happy hunting.

i didn't mention that when i first started trying to trouble shoot this i was having other elect. problems (long and aggravating story) but i had to replace entire wire harness under the dash and use a new cluster. before this the gauge was working. when it was all together (dash not installed) i noticed the gauge not working. i first checked the gauge by grounding it and nothing happened. i then ran a jumper from the gauge to ground and still nothing. i then jumped 12v to the gauge and then also grounded and the gauge worked. i also checked the the wire from the gauge to the sending unit and that wire is good, so i know that somehow i'm not getting the 12v to the gauge. i'll take your advice and see what i can find...i'll keep you posted. thanks for your time and advice......kevin

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64 barracuda
64 valiant convertable
65 valiant sedan
65 signet
74 vw beetle convertable
79 E-250 4WD van
94 dodge dakota

Remove the sending unit from the head, and test it. I think it is just a thermistor.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

it's an already tested new one.

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64 barracuda
64 valiant convertable
65 valiant sedan
65 signet
74 vw beetle convertable
79 E-250 4WD van
94 dodge dakota