I have a 1967 Barracuda with the 273 engine. The temperature gauge has never worked. If I ground the purple wire that runs out to the sending unit the needle moves all the way to Hot and beyond.
This weekend it was nice and I went for a cruise. The temperature gauge never moved off of cold even after an hour on the highway. I started thinking and just for fun when I pulled into the garage I pulled the wire off the sending unit and measured the resistance between the tip of the sending unit and the threaded base, here's what I had:
Hot just garaged 276K Ohms
After sitting for an hour 440K Ohms
2 hours 2.6M Ohms
3 hours 3.0M Ohms
Overnight 6.7M Ohms
These resistances seem very high to me. I thought I read somewhere Chrysler changed the way the gauges worked in the early 70's. Is this true? Could I have the wrong sending unit? Were they different between years? Any help would be appreciated. Yes it is full of coolant.
This weekend it was nice and I went for a cruise. The temperature gauge never moved off of cold even after an hour on the highway. I started thinking and just for fun when I pulled into the garage I pulled the wire off the sending unit and measured the resistance between the tip of the sending unit and the threaded base, here's what I had:
Hot just garaged 276K Ohms
After sitting for an hour 440K Ohms
2 hours 2.6M Ohms
3 hours 3.0M Ohms
Overnight 6.7M Ohms
These resistances seem very high to me. I thought I read somewhere Chrysler changed the way the gauges worked in the early 70's. Is this true? Could I have the wrong sending unit? Were they different between years? Any help would be appreciated. Yes it is full of coolant.
