Temp Gauge testing

[LLindell]

We have asked this before but still cannot figure out how to test to see if the temp gauge is working on our '75 270. Actually, the alt & oil gauges don't work either. Gas gauge is sporadic. If someone can explain or send a schematic on how to test the temp it would be awesome. LLindell@yahoo.com if you have the schematic.

[77Travco]

If none of the gauges are working then it sounds like an issue to the cluster.\nTemp gauge sender is near the thermostat housing on my 440-3. Pull the wire off and turn on the key... gauge will read all the way to either "C" or "H". When you ground the wire to the block the gauge will full swing to the other direction. Testing the gas gauge is exactly the same but you may have to cut wire to the top of the tank to test.\nHopefully someone here can provide you with a wiring diagram.

[Acesneights]

Did you check the tech docs section ? I thought we had a few schematics but yeah what 77 said. Check all your fuses with a test light on each side as they sometimes look good but are corroded. Also removing the instrument cluster is a royal PIA and you need to treat it very gently if it is the fiber optic one. 75 could be either way.

[LLindell]

Thank you both. Lots of help & he understands it!! I will check the docs section.

[Acesneights]

Click this link:\n\nhttp://www.travcoforum.com/viewtopic.php?f=39&t=262

[Dave78Chieftain]

For new style dash (73 RM Series and later)\n\nBoth the Fuel and Temp gauges are electro-thermal devices which operate on a constant voltage supply regulator that is mounted on the rear of the instrument panel board. If both gauges are not working, then the problem is most likely the regulator. You can replace the regulator (Dodge P/N 2258413) or upgrade to a solid state version http://www.allpar.com/history/mopar/electrical2.html\nThe fuel sender is a 10 to 73 ohm sender. 10 ohms is full (low resistnace). 73 ohms empty (high resistance).\nIf dual tanks, I am not sure how TRAVCO monitored each tank. Dodge did provide a spot for a 2nd gas gauge which some RV Mfg's used. Other RV Mfg's (e.g Winnebago) used a relay, fuel selector valve, and selector switch to change between tank selection and monitoring.\nNote: Old style dash 68-73 had the regulator installed inside of the Fuel Gauge.\n\nTemp gauge is low resistance when hot (e.g short) and high resistance when cold (e.g open). Front of engine by the thermostat housing,\n\nOil gauge does not use the constant voltage source. Sender rear of engine, driver side, aft of intake manifold\n\n74-74 Wiring diagram

[Acesneights]

hey Dave, which one are you referring to with "new dash" ?\nFrom what I have seen Travco went from this style(gutted Travco, 3rd pic) to what my 75 has(fiber op, 2nd pic)somewhere in 75 AFAIK. The 1968??'s Back I think had the 1st pic.\nAFAIK he "probably" has the fiber optic one.(Only the illumination is)

[Dave78Chieftain]

I am referring to the instrument cluster Dodge provided with the chassis\n69-73 Dodge supplied instrument cluster was a rectangle unit\n\n\nFor 74 and later (starting with RM chassis designator)) instrument cluster used a 3 circle version\nWhile this is a Winnebago implementation, the gauge cluster mounted in the panel was supplied by Dodge with the chassis\n\n\nFor 74 and later here is a aftermarket remake of the Dodge printed circuit board the gauges are mounted to:\n\n\n\nThese are the instrument clusters described in the Dodge Motorhome Service manuals. Those manuals are where I acquire much of the information I refer to. Dodge made the chassis. TRAVCO and other RV mfg's built the house on that chassis.\n\nHere is a parts diagram of the standard 74 and later instrument cluster\n\n\nThe lower rectangle section is an Option Dodge started offering around 76. I have it in my 78 Winnebago (77 chassis)

[Acesneights]

Interesting. It looks similar to the Travco but not the same. I wonder if Travco in 74 tossed the Dodge one and made their own ?

[Dave78Chieftain]

I cannot see the gauges clearly in your pic however in order for the gauges to easily match the Dodge sending units used at that time, I suspect they used a custom dash with stock Dodge gauges of that era like this 73 Dodge D-100 Adventure one:\n\n\nThey would be mounted in the custom dash\n\nOr maybe a 61 Power Wagon dash:\n