My coolant gauge sometimes goes crazy and quickly bounces up to max, only later to bounce back to normal. This indicates some eletrical problem, and I have replaced wires and yet it still happens. I don't trust the guage.
When rebuilding my motor most recently, it was due to ticking coming from cylinder number 3. There was excessive gap between the piston and cylinder allowing the skirt to slap the cylinder wall. There are many reasons this could have happened. The most likely was a bad job by the machine shop that bore the cylinders. Another option however is that I overheated the engine. That is entirely possible since my gauge frequently lies to me and I had gone for a drive but later found the coolant was low. Now with a fresh engine, I need to avoid even the potential of that ever happening again.
The best way to do that is with an aftermarket coolant gauge. I opted to get a gauge matching my aftermarket voltage and oil pressure gauges. I thought the install was going to be much harder than it turned out to be.
The factory ford carb utilized a temperature sensitive vacuum manifold that tied into the thermostat housing. After installing my weber carb, I just capped off those vacuum lines. I decided to remove the manifold entirely and low and behold, my new coolant temperature sensor threaded right in! Amazing, something went well for once. The only downside of this location is that its pretty high up so coolant needs to be flowing in order for it to read an accurate temperature. Although it does not require the thermostat to be open to give accurate readings. If there are any air bubbles in the system, this sensor won't give you accurate readings whereas the factory sensor will.
I figure that is a okay trade for easy installation since this sensor is there for a second opinion, not to replace the factory coolant temp gauge.
I ended up installing the gauge into the last remaining dash vent hole that was no longer needed once I removed the AC.
The gauge looks and works great. I am very pleased with the results. Pictures
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| | | | | | | | | I came back later and secured the wiring | | | | | | | | | | | | | | | | | | | tied into dimmer, power, ground, ign wires for other gauges | | | | |