I have a 1993 Honda Prelude S, The guy told me the f22a1 2.2l SOHC was swapped in but I think it came stock with the S model. Anywho, iv been dealing with some problems relating to my cooling. The temp gauge inside the car rises all the way to redline, however, when I flip the key off and back on quickly, it comes back up as being around half. My fans dont come on consistently either, they either do when it hits a certain temp or just dont come on.

I believe iv narrowed the issue down to my coolant temp senor in the coolant inlet on the front of the car, however I know that controls the fans and theoretically shouldnt affect the gauges inside.

I found what I believe to be a new temp probe for the inlet however it looks smaller than whats in it already.

If someone could help me source all the temp sensors or at least give me names for what they are, that'd be terrific as im unable to find anything in my own searches aside from the one on the thermostat housing.

Thank you in advance

 

Any help would be appreciated, I really need to get this figured out but I cant figure out the issue.

 

Fan switch should be on the thermostat housing. Gauge sender should be on the passenger side of the head closest to the fan switch.

 

It could be the gauge unit being finicky. If the fans are coming on, and the car doesn't seem like it's overheating at all, then that's probably it. These things go bad after a while and they are almost 30 year old electronics in an environment with humidity and varied temperatures. There is a module in it called a "fuel/engine coolant temperature (ECT) control unit". If you can find a known good cluster to swap it with just to check it's operation that would be a good start. They aren't cheap working and it's not an easy thing to repair for a novice, but there are usually some on EBAY and a spare one is not a bad idea if you're driving it a lot.

 

Your coolant temp sensor is your culprit. That sends the signal to your gauge. Your fan switch is separate.
Try cleaning the plug and the sensors connector pin first and see if it works, might just be soaked in oil or loose connection. If it still gives you problems, just hit up a wrecker and grab a few for dirt cheap or buy a new one.