Car ran fine all winter. This spring, I noticed if I had the car up to OT and let it sit and idle, the temperature would creep up. The temp gauge usually sits 1/4 of the way up. When it would creep, it would go up to 1/2. I remember my fan used to work, but now it doesn't. Today I flushed the radiator and replaced the thermostat. It seemed to run perfectly when I started it up. After it was up to OT and it sat for a few minutes, the temperature creeped back up again. As soon as I got on the road it came back down, like always. Why isn't my fan working? Where is the fan switch? Do I need to order a new fan switch for an 85 CRX Si or for a 90-91 Integra or what? Should I check the relay? Can I check the fan? Thanks guys.

 

check the wiring and the themo switch.

There is a plug on the back of the block, heat it up and see if current flows through it once its brought up to about 190 degrees.

its a bitch to get to, have fun w/ that.

 

I'd rather just replace the switch than heat it up. What car do I order a switch for? Setup is in sig, 85 CRX Si with a B16A1.

Also, when I got home from driving around for a while, I felt the top hose, and it was hot. I felt the bottom hose, and it was almost, if not just as hot.

What wiring is there to check? Where exactly is the fan switch? Looking at the engine from the tranny side, I thought the sensor under the exhaust cam was the Coolant Temperature Sensor for the ECU, and the sensor to the left of that was for the temperature gauge?

 

its not near that, its on the back of the block. To buy a replacement, buy one for a 90-91 integra LS. You need to make sure that the unit is defective before just buying a replacement. If the wires came undone or there is an electrical problem elsewhere, spending all that money at honda is pointless. The fan switch is the first place to start. Basicly, when the block heats up, the thermoswitch heats up aswell. When it gets to a certain point, it starts to conduct electricy, and that allows the fan to turn on. These units go defecitve from time to time, hence that would be the first place to check.

You putting your hand on the upper and lower radiator hose simply shows that your radiator is working and your thermostat is working aswell.

You just need to worry about hooking up the fan.

 

If you cant get to the thermo switch or its to much of a pain you can run a line to the fan through a switch from the battery. Search for "fan switch" and stuff like it, theres been a few writeups on it plus its quite cheap. It can get annoying after time having to switch the fan on and off but its a lot simpler than trying to get that damn thermo switch out of the block.

 

I see 3 sensors in the block here. Which one is the thermoswitch?

 

none of those...

its the sensor on the rear of the block (near oil filter) that is green in color and has a 2 wire plug.

 

Just looked back by the oil filter. I see a green connector with one red wire coming out directly above the oil filter, but right underneath the IM. I see a grey connector with one wire to the left of the oil filter. Which one?