hey guys!!! i've had the same problem all winter and now i'm really getting pissed!!! my car just won't heat up!! though it was the thermostat so i take it off put it in boiling water and it seem's like it works just fine!! so bleed the system again!! and then i realize that the fan go on when the temp gage goes higher than (little lower than quater) and then it drops back to cold!! and i forgot to say this is when i press the pedal to the metal!! otherwise it stays at C= cold! so i though of the fan switch i replaced it and the same thing happen!! if i unplug it and REV it up for a long time it gets to normal temperature but as soon as i start to drive it temp drops again even with the fan switch A(cause there is 2)unplug! the other fan switch turn on the fan at the exact good temp(normal operating temp)..
so i'm thinking of 2 possibilities 1- the gage sensor doesn't work properly but it doesn't make sens cause i see the temp gage go up and down all the time and the 2nd fan switch turn the fan on at the exact temp of a normal engine operation!
2- I DON'T KNOW!!!! please send me idea or whatever !! would you change the thermostat anyway see if there'S a difference??? i though of placing cardboard in front of my RADiator but that sucks!!! it was working properly and i want it to work properly again!! please no stupid answer !! only ppl who know what there talking about!!

 

Coolant Temperatue Sensor

 

the 1 for the ecu?? it doesn't control the fan !!! it just tells the ecu what temp ur engine is at!! there 1 for the gage inside 1 for the ecu 2 for the fan!!

 

First of all what year?

 

it's a 95 engine obd1 fitted into a accord wich i modified and kept the 2nd faN switch i'm talking to u about!! but the wiring for the 2nd fan switch doesn't pass to the computer.....neither those the 1st fan switch!!

 

What year accord? You gotta help me out here

 

if you disconnect the gauge sensor and ground the connector, your temp gauge should go to hot (all the way to the top of the gauge). if it goes to hot, then you know the gauge is functioning the way it should. then you can start replacing coolant temp sensors. you might replace the thermostat just for good measure, but it doesnt sound like your problem

 

hey!! thx man didn't though of it! let say it does goes up(cause i don't have that car right now) i know i replace the fan switch A to see the reaction(cause i had another 1 at hand) and it was doing the same thing(fan was starting at less than the quater of the gauge..) it can' t be the ECT sensor for the computer that's for sure... so the only 2 option left are a big air bubble is stuck near my fan switch A or the thermostat doesn't open at the right temp(cause i didn't have a termometer but i saw it was completly open)! so anyway i'll try that has soon as i get the car back and if it goes up than i'm gonna change the thermostat to be sure!! hey just wanted to know ...last 2 time i got to buy a thermostat for my h22a nobody had the right sizes thermostat but i didN'T get to honda yet! u guys think they'll have the good one???? it's a JDM engine is there a difference in beetween the usa thermostat model and the JDM??? thanx!

 

probably no difference for jdm and usdm. you'll have to ask the dealership, but since they are the same block and head it probably doesnt matter. but yeah..anyways see if the gauge goes up and if it does replace ther thermorstat for good measure and replace the gauge temp sending unit

 

ya!! thanx...i replace the thermostat!chek the gage for normal operation and it does work properly. so ya the only thing left to do would be to chek the gage sending unit!! i'll chek that tomorrow any1 got spec for the temp gage sending unit???