Temp gauge mystery

[RedFish]

Hi Red. First time I learned of one of those was way back in 67 before I joined the Navy, had a '60 falcoon for a short time. The IVR shorted and pegged both gauges. "Intuition" told me that they both cant be bad, felt around back there with one hand and jerked the IVR out. Found it mostly by hope, luck, and feel. Went downtown, bought a new one, and away we went. "Kid's luck" LOL

I think maybe GM is about the only outfit who did not use them

Yeah Fords limiter attached just like a 9VDC radio battery. Their circuit board weren't boards but copper traces laminated in vinyl. Battery fasteners mounted through that vinyl too. Today that material might crumble. Now back to our regular programing (Buy replacement limiter? Build a IVR or buy one?)

 

[dodgemahal]

Redfish,
Thanks for your input. Your post peaked my interest, but I'm having trouble following. To boil it down, are you saying the gas gauge could be operating normally yet the temperature gauge could have wild swings and not function because of a bad limiter? Those are my symptoms.
I have a solid state limiter ordered. I've used them in the past. I have no idea why I didn't make this a priority; instead I installed Rockauto sourced electro-mechanical limiter. It's new, but maybe bad!

Been here more or less since 2007. Hashed this over a few times. Wild needle swings are a symptom of failing mechanical limiter.
Too much juice from the limiter wouldn't effect the temp gauge with a cold water signal. The fuel gauge is drawing it at that time. That needle climbs real good. When the water is hot the temp gauge draws all that juice.

 

[cudamark]

Redfish,
Thanks for your input. Your post peaked my interest, but I'm having trouble following. To boil it down, are you saying the gas gauge could be operating normally yet the temperature gauge could have wild swings and not function because of a bad limiter? Those are my symptoms.
I have a solid state limiter ordered. I've used them in the past. I have no idea why I didn't make this a priority; instead I installed Rockauto sourced electro-mechanical limiter. It's new, but maybe bad!

My experience with them is that the IVR affects both gauges equally.....assuming the circuit board is in good shape and all connections are sound.

 

[dodgemahal]

Mystery solved. Bad gauge. I put together this Rube Goldberg test apparatus. Tested two good ones and the one in my instrument cluster. It was bad.

 

[RedFish]

I

Redfish,
Thanks for your input. Your post peaked my interest, but I'm having trouble following. To boil it down, are you saying the gas gauge could be operating normally yet the temperature gauge could have wild swings and not function because of a bad limiter? Those are my symptoms.
I have a solid state limiter ordered. I've used them in the past. I have no idea why I didn't make this a priority; instead I installed Rockauto sourced electro-mechanical limiter. It's new, but maybe bad!

I didn't intend to suggest a fault in your fuel gauge. If you put a ohms meter to them you'll find the temp gauge to be the same 20 ohm gauge as all others had been for years. Your fuel gauge should measure 13 - 13.5 ohms. Not as accurate but lives longer than its 20 ohm predecessor. If you've found a fault with the temp.gauge,, thats fine. I can't image a condition within the gauge that cause the symptom you describe. Good luck