3.2 in a 914, CHT times 2? Options

[NARP74]

The car I bought a little while ago had a 3.2 in it with stock FI and engine mgmt. That includes a CHT for the computer. At the last minute, the selling agent I was buying the car from decided to put in a center console with a CHT gauge. He did not have anything to drive the gauge so they hooked up a real fast solution just to get the gauge running. See the pic...

The problem is that where and how it is located, it pretty much just reads 0 or 350, nothing else. It never reads lower, never cools off. It is right by the exhaust manifold. The 3.2 has a built in CHT. Can I buy a new temp ring and tie it in under the factory CHT on cyl 3 like the factory? Is there room under the plugs on a 3.2 for the CHT ring like it would be hooked up on a 4 cyl? I have not looked into the plug area to see if there is any room. I don't think I can split the output of the factory CHT or it will change the resistance, I am guessing.

What have others done to feed a CHT gauge on a 3.2?

[targa72e]

From the picture that is pretty much no sensor. Looks like a standard terminal tied to ground. I do not know what your gauge is expecting from a sensor but currently it looks like you have no sensor. There are a couple different types of sensors to measure temperature they work differently.

A thermocouple is a two wire device. It is made of two dissimilar metals that create a small voltage in response to temperature change. These can be very inexpensive sensors as it is literately two wires of dissimilar metal soldered together. Downside is voltage is so small any noise can cause problems. Not typically use by on cars from OEM'S. These are often aftermarket and either go in exhaust or under spark plug.

Next there is RTD (resistance Temperature detector) and thermistors. These can be a one or two wrire device. They work by having a material that changes resistance to heat. You can have positive or negative sensors. On the positive they increases resistance with more temperature and the other, negative ,decreases resistance with temperature. These are the most common type found in automotive applications. The sensor cost a little more but can work with one wire (other side is engine ground which is why engine grounding is so important) or two wire (where on side is tied to ground).
The fact that your current sensor reads 0 or 100 percent (probably ignition on or off) indicates it is most likely expecting a RTD or thermistor sensor

john.

[NARP74]

From the picture that is pretty much no sensor. Looks like a standard terminal tied to ground. I do not know what your gauge is expecting from a sensor but currently it looks like you have no sensor. There are a couple different types of sensors to measure temperature they work differently.

A thermocouple is a two wire device. It is made of two dissimilar metals that create a small voltage in response to temperature change. These can be very inexpensive sensors as it is literately two wires of dissimilar metal soldered together. Downside is voltage is so small any noise can cause problems. Not typically use by on cars from OEM'S. These are often aftermarket and either go in exhaust or under spark plug.

Next there is RTD (resistance Temperature detector) and thermistors. These can be a one or two wrire device. They work by having a material that changes resistance to heat. You can have positive or negative sensors. On the positive they increases resistance with more temperature and the other, negative ,decreases resistance with temperature. These are the most common type found in automotive applications. The sensor cost a little more but can work with one wire (other side is engine ground which is why engine grounding is so important) or two wire (where on side is tied to ground).
The fact that your current sensor reads 0 or 100 percent (probably ignition on or off) indicates it is most likely expecting a RTD or thermistor sensor

john.

I'll pull the gauge and run the numbers to see what it came with or what it needs. Thanks for the info.