it's been puzzling me for the longest time possible, believe me. why are there 2 thermosensors on my 1990 civic 4-door dx?

you see, i have this problem : i think that my thermostat is opening too early (i see my temp gauge 1/4 of the gauge most of the time). but my rad fan doesn't turn on until about half of the gauge. so i'm planning to change the thermostat with an OEM one (my brother-in-law said he changed it to an aftermarket and colder thermostat when he changed it before).

so that i won't again have the same problem (rad fan turns on late and not turning off until you shut the engine off), i'm also replacing teh thermoswitch (thermosensors). i'm confused because i don't know which thermoswitch should i replace

anyone? thanks

 

There are two thermoswitches? Mine only has 1 by the thermostat, and then a coolant temperature sensor, that's it.

 

you have 3...kinda.

1-wire under dizzy= for gauge
2-wire under dizzy= for ECU (aka: ECT, engine coolant temperature sensor)
2-wire on back of block=fan switch

 

according to the online honda parts, #23 and 24 are the thermosensors and #22 is the temp sending unit?

if the rad fan is turning on late (or is it the thermostat opening way too early), what parts should i replace? i'm so fed up already of my rad fan not turning off once it turns on (unless you shut the engine off). it's so noisy

 

23 controlls the fan.
22 is for the cluster.
24 is for the ECU.

 

does anyone know what the connector for #23 look like?

 

I'll keep looking for a pic, but if you are working on it now this might get you through -

It's an ugly big rubber boot. The actual connector leads can slide in and out from the boot. It makes no difference which pole on the switch you hook the connector leads to - it's just a switch and turns on and off.

 

ok so heres the thing. i have a d15z1 block.

does it only have # 21?

cuz if it has both im ****en blind

 

Check up on the thermostat housing for that engine

 

thats were the rad fan input is?

 

yeah, shoulda mentioned the swap

 

so like....

i still cant find that input

 

4drEF, what do you think is wrong in my car? once the rad fan turns on, it doesn't turn off unless i shut the engine off thanks

 

make sure the thermostat is installed with he air bleed pin at the top.

 

Is it cooling down properly or is the fan actually on for a reason?

Only things that come to mind are the fan switch or a sticky relay.

 

so # 23 on the d15z1 should be under the thermostat housing for my engine? cuz i had to figg another fan cuz the rad fan never came on=/

 

thanks, man. i think i'll have to flush my cooling system first just to be sure