Check out some similar questions!

VegasNut · Apr 3, 2007, 09:24 PM

I am trying to figure out the cooling fans on my 89 Honda CRX. I will try to explain. First my Honda CRX has two cooling fans on the radiator. Neither fan would turn on even though the temp gauge would get almost red line hot before I would just turn it off.
I changed the fan relay on the right side of the car near the battery and now the small fan in front of the engine stays on when the ignition is on. The second fan (in front of the Trans) still never comes on, but now the temp gauge never gets past half way with the first fan going all the time. Good thing I guess.
I have checked all the fuses, tested fan motors and checked temp. sending unit. Now I noticed that there is a second relay on the small fan's shroud (the one that stays on) and when I disconnect that relay the fan turns off, but the other fan will still not come on.
Can someone explain to me how these fans work? And, What may cause the one to stay on all the time? Is it meant to be that way and the second fan only turns on when needed??
Thanks for the input.

hiperf402 · Apr 4, 2007, 04:47 AM

Older Hondas have the fan switch in the bottom of the radiator. If your thermostat doesn't open, the fan switch never sees hot coolant to turn the fans on.

VegasNut · Apr 4, 2007, 08:00 AM

Originally Posted by hiperf402

Older Hondas have the fan switch in the bottom of the radiator. If your thermostat doesn't open, the fan switch never sees hot coolant to turn the fans on.

Thank you, but I have already changed the radiator, hoses, thermostat, and water pump. There is no switch in the bottom of the radiator in neither the old or new one. From what I understand there are two relays for the fan motors. I am just not sure what tells them to turn on.

FixHondas · Apr 6, 2007, 10:28 PM

The thermoswitch on your CRX is in the block, below the intake manifold. IF you have A/C, both fans should come on when you turn the A/C on. Is this the case?

VegasNut · Apr 6, 2007, 10:48 PM

Originally Posted by FixHondas

The thermoswitch on your CRX is in the block, below the intake manifold. IF you have A/C, both fans should come on when you turn the A/C on. Is this the case?

Not at the moment. Currently the A/C fan is on weather the A/C is on or not. In fact when you simply turn on the ignition, but not start the car, the fan comes on. We have not been able to get the main fan to come on without hooking it straight to the battery to be sure it worked at all.
However we have determined that one of the fan relays is bad. It seems to be stuck open. The only way to get the fan to turn off is to unplug that relay. I am going to replace that relay and the thermal switch tomorrow.

Thank you very much for your help. Specially locating the thermal switch. Any other advice is greatly appreciated.
By the way. On the CRX we have 4 relays that seem to be related to the cooling system. One on the A/C cooling fan shroud, two mounted just behind the passenger side head light and one on the passenger fender by the battery. Can you tell me which relay is for what?

Thanks Again.

FixHondas · Apr 6, 2007, 11:21 PM

According to the ETM, the two relays by the battery, one is the A/C clutch relay and the other is the condenser fan relay (condenser fan is on driver's side).
The condenser fan relay gets power from dash fuse #18 on blk/yel wire (hot in run). The blu/red wire is a ground that comes from the diode (which separates signal from ECU and thermoswitch). If you short what and blu/blk together fan should run. If not, check under hood fuse#38.

The relay on the fender by the airbox is the cooling fan relay. The coolant temperature switch supplies ground to this relay on the yel/grn wire. Dash fuse#15 supplies power to it on blk/yel wire (hot in run). Short blk and blu wires together and fan runs.

There is a noise suppressor mounted to the condenser fan shroud. I can't locate what the relay on the shroud is for.

VegasNut · Apr 7, 2007, 07:30 AM

Originally Posted by FixHondas

According to the ETM, the two relays by the battery, one is the A/C clutch relay and the other is the condenser fan relay (condenser fan is on driver's side).
The condenser fan relay gets power from dash fuse #18 on blk/yel wire (hot in run). The blu/red wire is a ground that comes from the diode (which separates signal from ECU and thermoswitch). If you short wht and blu/blk together fan should run. If not, check under hood fuse#38.

The relay on the fender by the airbox is the cooling fan relay. The coolant temperature switch supplies ground to this relay on the yel/grn wire. Dash fuse#15 supplies power to it on blk/yel wire (hot in run). Short blk and blu wires together and fan runs.

There is a noise suppressor mounted to the condenser fan shroud. I can't locate what the relay on the shroud is for.

Thanks a million. I think this will help me out a bunch. We noticed that the cooling fan relay has power to three of the four prongs. If the thermal switch supplies ground then that may be where my problem is. I will let you know as soon as I have the switch and relay changed.

VegasNut · Apr 7, 2007, 11:29 PM

Originally Posted by VegasNut

Thanks a million. I think this will help me out a bunch. We noticed that the cooling fan relay has power to three of the four prongs. If the thermal switch supplies ground then that may be where my problem is. I will let you know as soon as I have the switch and relay changed.

Switched out the Thermo Switch. Now when the car warms up the A/C fan goes on and off as the main fan should, but the main fan will still not come on. Their must be something hooked up backwards that is cause this A/C fan to cycle as the main fan should be.
Still working.
Thanks.