dsettlemoir

90 Accord

Condenser fan not kicking on. Radiator fan works fine.

Condenser fan does work when wired directly to battery so we know the motor is good.

I have no power coming INTO the condenser fan relay (mounted to front of vehicle near the fan)

Ive check jumped the temp switch and checked all fuses.

Is there something else that is in the system that sends electric to the condenser fan relay!

masospaghetti

There's two fan switches, did you check them both?

Scroll down to post #7 for very detailed information on the system. My gut tells me one of your fan switches is bad.

Cooling fans not working at all. - CB7Tuner Forums

dsettlemoir

Good info. Switch B I did jump and with no results. Switch A is something I have not jumped.

I may try jumping it tonight when I get home and see if that helps.

dsettlemoir

Could either switch allow the radiator fan to work but not the condenser fan?

StokelesS_g2

Do you have AC?

dsettlemoir

yes. Very cold unless stopped in traffic. if I can figure out how to get power to the fan then I'll be great.

StokelesS_g2

Just wire it to the other one.

masospaghetti

Bad idea, you are running two fans from a power source meant for one fan, easy way to blow relays, melt wiring, and pop fuses.

Did you check your fan switch yet? You could try jumping the two wires together at the connector and see if that turns the fan on. Or get a new one.

@ Rockauto

STANDARD MOTOR PRODUCTS TS187 {Click Info Button for Alternate/OEM Part Numbers} Intermotor Info
ON THERMOSTAT HOUSING $13.46

STANDARD MOTOR PRODUCTS TS254 {Click Info Button for Alternate/OEM Part Numbers} Intermotor Info
On Water Outlet $19.08

StokelesS_g2

Well then, run a wire to the battery with an inline fuse to a relay and use the radiator fan + as an activation switch.

fcm

The ECT switch has nothing to do with the condenser fan, if you have no power going to the condenser fan relay, find out why and fix it, jerry rigging the condenser fan is not a good idea.

I do not have the wiring diagram for a 90 Accord, but I can tell you the condenser fan relay plug should have two powers going to it, one is most likely a 12V constant, ^for fan power, the other is most likely switched, hot in run, and is power for the relays coil, relay control is a ground. 94

dsettlemoir

I haven't had a chance to check the switch A yet. i hope to today.

I'm not throwing any codes that suggest one of the switches is bad but I also realize a code may not be thrown as long as the switches are simply plugged in

masospaghetti

A bad fan switch will not throw a code or check engine light.

fcm

Or have any effect on the condenser fan. 94

masospaghetti

I don't think that's true based on this thread: Cooling fans not working at all. - CB7Tuner Forums

The Condensor Fan Relay can be grounded by: Switch A, the Powertrain or Engine Control Module (PCM or ECM), or the A/C Circuit.
The Radiator Fan Relay can also be grounded by: Switch A, the Powertrain or Engine Control Module (PCM or ECM), or the A/C Circuit.

Just to be clear, Switch A is the one on the thermostat housing. Switch B is on the water outlet. (The referenced thread mixes these up in words but shows it correctly in the pictures.)

dsettlemoir

Considering they are original, there is a good chance one or both are bad.

I appreciate the help. I'll give updates after I replace both.

holmesnmanny

We already told you that those switches don't cause one fan to run and the other not to run. It's likely the fan control unit/timer is going to be the culprit here. You can do some searches to find it's location. I forget at the moment. You can get them at the junkyard. I'm sure there are a few threads that will show you the correct test procedures and illustration you just have to do some searches. I'm not sure where my 91 accord helms is at the moment.

masospaghetti

Based on the wiring diagrams, it looks like Switch B could cause only the condenser fan to fail.

I could be wrong. I'm just looking at the wiring diagram.

fcm

That is confusing The ECT switch controls the rad fan and only the rad fan, the ECT sensor supplies engine temp. info to the ECU and only the ECU, the ECT sending unit sends engine temp. info to the cluster temp. gauge and only the temp. gauge, condenser fan is controlled by the A/C switch, A/C diode and Rad Fan Control Module, the RFCM also turns on the rad fan when A/C is turned on even if engine temp. is below ECT switch trigger. 94

tech8

Coolant Temperature Switch A controls both the radiator fan and condenser fan. As you can see in the attached circuit diagram, when Switch A closes, ground is sent to the separate condenser fan relay and radiator fan relay.

tech8

The A/C condenser fan is on the driver side and the radiator fan is on the passenger side.

With the ignition to ON or START, if the coolant temperature is above 194 degrees F at engine coolant temperature switch A (located on the thermostat housing – connected to the lower radiator hose), then the switch will close, which should turn on both cooling fans (radiator fan and A/C condenser fan).

With the car running, if the A/C is turned on, both cooling fans should run, regardless of the coolant temperature at the Switch A.

When you shut off the car and the coolant temperature is above 226 degrees F at the engine coolant temperature switch B (located on the housing connected to the upper radiator hose ), the radiator fan will run until the temperature drops at Switch B (which opens the switch) or up to ~ 15 minutes.

Both Switch A and B are normally open type of switches, and close when the coolant temperature is above the respective temperatures.

If you were to disconnect the 2P connector to the coolant temperature Switch A, and jump the connector with a piece of wire or small paper clip, then turn ignition to ON (II); both fans should run.

************************

1. Jump the connector for Switch A, does both fans run? If the condenser fan does not run, then the issue can be either an open (break) in the wiring, faulty condenser fan relay, or faulty fan timer unit.

2. At the harness connector to the condenser fan relay, there should be 12 volt power on white wire at all times. With the ignition switch in RUN or START, there should be power on the Yel/Wht wire. Check for power on both these wires.

3. If there is power on the white wire to the condenser fan relay harness, use a jumper wire (spare wire) and connect pin 1 (white wire) to pin 3 (Blu/Yel wire). Does the condenser fan run?