Heat sensors

[roanokeSpider]

The two heat sensors on the cylinder head might have been switched around when the valves were replaced. How can i tell which controls the fan and which controls the guage (colors)? Also since the guage runs off of resistance are there any more accurate alternatives? Similar to how you can replace the oil pressure guage with a mechanical one.

[So Cal Mark]

both sensors in the top of the head control the temp gauge. The fan switch is in the bottom of the radiator. As for replacing the gauge with a mechanical unit; sure, you just have to get the proper threaded adapter for the cylinder head