My fan wont turn on so my car keeps over heating, I replaced the swtich on the thermo housing. does anybody know what else could it b?

 

anybody? lower radiator hose gets hot so i know it cant b the thermostat

 

get a new fan? or radiator?

 

i jumped the fan to the battery 2 test it an it works fine, radiator is brand new

 

what model is it i will get you some info.

 

ok here is some info ona 2000 civic
Fans
How the Circuit Works
Radiator Fan
Voltage is provided at all times to the radiator fan
relay (contacts) through fuse 57. With the ignition
switch in ON (II), voltage is provided to the coil of
the relay through fuse 17.
The radiator fan relay can be grounded through
either the engine coolant temperature switch or the
engine control module (ECM) or powertrain control
module (PCM).
The engine coolant temperature switch grounds
the radiator fan relay (coil) when the engine
coolant temperature exceeds 199F (83C). The
switch opens when coolant temperature
decreases 3– 8C.
Condenser Fan
Voltage is provided at all times to the condenser fan
relay (contacts) through fuse 56. With the ignition
switch in ON (II), voltage is provided to the coil of
the relay through fuse 17. When you push the A/C
switch and put the heater fan switch in 1, 2, 3, or 4
position, the A/C thermostat comes on, the
condenser fan relay energizes, and the condenser
fan motor runs.
A/C Thermostat
The A/C thermostat is located on the evaporator
housing. The A/C thermostat turns off the A/C
compressor clutch if the temperature at the
evaporator goes below 3C (37F). This prevents
condensation from freezing on the evaporator fins
and blocking the air delivery into the passenger
compartment. If the temperature goes below 3C
(37F) turning off the A/C thermostat, ground will be
removed from the condenser fan relay. This will
deenergize the relay and remove voltage from the
condenser fan motor causing the fan to stop running.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.

 

Did you check the relay in your engine base fuse box?

 

yea i bought a new relay it still dosent work and its a 98 honda civic ex

 

i once was told that the coolant fan switch sensor, even if bought brand new, could be defective...unless you have a break in that sensor's wiring...just a thought...gl...mines the same...still can't figure out what is wrong with the thing...just rigged a toggle switch on to turn it on and off whenever i want...

 

Thanx not sure if its the ecu though,
Gonna try a different ecu and see if that's the problem

 

check the wiring, i had a wire that was cut that made the fan didn't turn on for the thermoswitch.

 

use jumper to try if the fun is really working... and if yes, look for the wires specially on the connectors...

 

ill check the wiring tonight but last time i checked it was ok all the connections was fine and pluged in, i jumped the fan to the battery and the fan turns on, the car has a new radiator, thermo swtich, thermostat works fine, radiator fan works, new relay, i think i am going to check the wiring an fues 1 more time

 

wiring is fine dont know what else could it b

 

ok here is a diagram of a 2000 civic since you failed to give more info on year since they are diffrent from gen to gen

 

ttt i turned my ac fan the radiator fan doesnt come on, i was told that they were suppsed to both come on when i turn the ac, but the radiator fan doesnt come on so iam thinkin it has to b the relay

 

have you check the censor that sits on top of your thermostat ? I went trough the same crap you did and that was my problem. good luck.

 

sensor is brand new

 

damn gl

 

thanx