Hello,

First post here... My temperature gauge in my car (1994 Honda Accord LX) shows RED HOT, but i know its not overheating. I suspect its the coolant temperature sending unit.

Can anyone tell me where it is? It looks like the car has two temp sensors, one at each radiator hose where it goes to the engine.

Thanks!

 

On my 92, there are three temp sensors nearby each other, close to the distributor -- in fact, two of them are under it. You can remove the wire connector from a sensor and see when your temp light goes out -- that is your unit, probably the thinnest one of the three. Good luck.

 

So when i remove the correct plug, the temperature should then go all the way down? or all the way up? not sure i understand what you mean by the light goes out.

Thanks again!

 

If you pull off a wire connector (no need to take out the sensor yet), with a gauge, the needle should go down to zero. If you have only a warning light, it should go out.

 

Thanks for your reply!

This morning I tried unplugging each temp. sensor one by one and then looking at the temp gauge... the gauge was unaffected by unplugging the sensors.

Could it be that it needs to have a new sensor plugged in, in order for it to read correctly? Maybe the old one has a break inside the wiring or connector, so it will only read correctly when its not showing infinite resistance?

Thanks again!

 

thermostat issue?

 

No I dont think its a thermostat issue...the gauge shows all the way hot, as soon as i start the car up, even after its been outside all night in below freezing temps.

I just went to Autozone and bought one sensor, when i plugged it into one of the connectors (there seems to be one at both coolant hoses coming from the radiator) the gauge still reads where it was.

I took a ohm meter and measured the resistance of the new gauge, and it shows about 1750 ohms to start, and as it heats up in my hand, resistance drops. Howver, at both the sensors in the car, it shows infinit resistance! Possible that both the sensors in the car are bad? I bought this car used so i dont know too much about the history of the car..

When i plugged the new sensor into the front plug, when i shut the car off, the cooling fan comes on. When i take the plug and put it back to the sensor in the car, it doesnt do anything.

Any ideas? Should i go back to the store and buy another sensor and change them both out?

Thanks!

 

Update- so i bought a second coolant temp sensor, and plugged both sensors into both plugs temporarily (so i didnt install the sensors into the housings yet) to see if the gauge would read correctly... still reading all the way hot! Would it make a difference if i installed them correctly into each housing on the car?

I checked for voltage at each sensor, and each of them shows 12V output. Is there another location or another sensor that controls the temperature gauge?

Thanks!

 

If the gauge does not fall to zero when you unplug the proper connector, the gauge most likely is defective.

 

I found out which connector is the correct one that controls the gauge... when i unplug it, the gauge goes all the way to zero. When i plug it back in, it goes all the way hot again.

So would this mean that the sending unit itself is bad? if so I'll stop by a Honda dealer this morning to see if they have one in stock.

Thanks!