JH4DB858

I replaced the thermostat, radiator fan switches, and relay. With the car running I jumper the connector from thermostat housing fan switch, the fan kicks on. Then with the car of turned off I jumper the switch from the front of the head the fan kicks on. So I know the relay I replaced works and the fan works. The switches are new. Anyone have any other ideas why the radiator fan won't kick on? I also bleed the whole coolant system.

ITR_bham

Is the car overheating?After you have had it running for a while and the fans are not turning on, what does the lower radiator hose feel like? Is it cold or warm?I just went through this with my accord.

JH4DB858

haven't had it to the point of over heating on the temp gauge. I drive for 30 mins. open the hood and can hear radiator boiling. I'm just about ready to say F it and run the fan with a toggle switch.

holmesnmanny

Buy a Honda OEM thermostat.

Turn the temperature control **** in the car all the way to full red.

Drain the coolant. Place OEM thermostat in the thermostat housing.

Jack the front of the car up as far as it can go. Open the bleeder valve on the thermo housing. Fill the car with coolant until coolant comes out of the bleeder valve. Close bleeder valve. Continue filling. Just close the cap. Start car. let it warm up until fan comes on. If it gets to mid level on gauge before fan comes on, turn off car.

Repair open in wiring. This assumes all parts installed are OEM and new.

ps. Your car may not be getting hot enough for the fan to come on yet.

phootbag

You need a pyrometer ( infrared temp gun ). Measure the temperature of the radiator, upper and lower hoses and thermostat housing area.

If you have an air pocket at the switch it could explain why the fans won't come on and you hear "boiling" which could just be air making a gurgling sound as it passes through the system.

You need to measure the actual temperature of the system. The fan switch may just not be at the temp needed to cause the fans to cycle. There may not be a problem with the system.

holmesnmanny

Yeah, I've bought aftermarket fan switches and thermostats that simply just weren't made right or were for a different temperature than the car is made for. I normally just go OEM nowadays for those parts.

phootbag

There is a good reason why one company's parts are cheaper than another.

I saw a judge ( something or other ) court show and she said her grandma has a saying, "cheap is expensive". She's right. Buy something once, or buy it a hundred times. Which will be cheaper?

Lost Again

If he is jumping the switches and only one fan is coming on.......I don't think the "quality" of the switch is at fault. Each fan has a relay and fuse- assuming the motor is good....sorry, I read this as the OP is only able to get one fan to run when doing these tests....thermo a should make BOTH run, themo b only one .....boiling is almost- almost- always due to air in the system.