Cylinder Head Temp Gauge, Step By Step Instructions Options

[Allan]

Did a search but didn't find much. I'm looking for good, clear, step by step instructions on installing one. Car has no center console if that matters...........

[lapuwali]

There are two wires and you must run both of them from the sender to the gauge. Most other types of senders measure the difference in voltage between +12 and ground through the sender (a thermistor, which varies resistance based on temperature) and +12 and ground through a fixed resistance. So, they only need one wire from the gauge to the sender (which then goes to ground through the variable resistor).

The CHT gauges, however, are thermocouples, which generate a voltage themselves based on the difference in temperature between the two ends of two different kinds of wire. One end is soldered together and crimped to the ring terminal at the spark plug. The other ends are in the white plug. The generated voltage is very weak (millivolts), and only works if you measure it across the two wires.

The exact length of the wires given with the harness isn't critical. It shouldn't be WAY shorter (like 1" instead of 15'), nor should it be a lot longer, but it can be half or double the given length w/o throwing off the measurement by enough to matter.