No main fan or AC fan

[hiker88]

Please disregard my last post. There has been a slight development, but I don't know what it means.

I really wanted to make sure the fans were bad. I removed the driver side fan from the car and exposed the wire pins from the plastic plug. I attached 12vdc and the fan spun. I put it back in the car, connected it, and started the car with the AC on. The driver side fan, TEMPORARILY comes on (about 2 seconds) then it clicks off.

I disconnected it the driver side fan again, left the fan installed and connected 12 vdc again to the driver side fan. The fan comes on and runs as long as I leave power connected. I reconected it to the car, and again, it comes on for about 2 seconds and then shuts off.

Is the driver side fan the main or sub fan? I'm going to drive it back home with the A\C to see if I can get the car to warm up. If I can get it warm enough, I will see if the driver side fan comes on without the AC engaged.

Any ideas?

[hiker88]

So here is where I am at now.

The driver side fan cycles on and off based on radiator temperature with the AC off.

The driver side fan does the same thing with the AC on, it cycles on and off. The car is no longer over heating with the AC on, but the passenger side fan does not come on and the air with the AC on is lukewarm at best.

I suppose its possible that the passenger side fan is bad?

[plain OM]

Driver side fan is the main fan; passenger side fan is the sub-fan.

I'm pointing at bad contacts in the connectors to the two fans. They're exposed to the elements as well as the heat of the engine, so it might not be unusual after a few years, especially in areas where there's winter conditions such as salt and lots of moisture. (If this turns out to be the case, I'm going to check mine as well.)

The fact that the main fan seems to be working now after the connector was, in effect, reconnected a couple of times, is the key. Also, in light of the series/parallel configurations, it appears the main fan is working when the ECM is calling for high speed fans, with the sub-fan still not functioning. When the main fan goes off after a few second, it might be that the ECM is calling for slow speed operation, but because the sub-fan is now in series, if it's connector is bad, neither motor will work.

For the AC to work properly, the high pressure refrigerant going through the condensor has to be cooled down by the fans in order to condense. If only one, or neither, is operating, the hot refrigerant will not condense fully. This will reduce the degree to which the evaporator can cool the cabin air passing through it, and this could possibly be the reason for the lukewarm AC output.

I'd try the same thing with the sub-fan. Remove the connector, apply 12 V to test, reconnect a few times to clear the contact surfaces, and see what happens under the different conditions. (If the fans are working properly, the temp gauge will not move from the normal position.)

This thread (main fan and sub fan not working ) has a similar problem, and also had the main fan finally working. In that case, the sub-fan was in fact bad, but do check the fan motor and connections before, as you did for the main fan.

[ETC]

Unless something changed, it's pretty straightforward. Mine has two separate fans, the bottom sits in a bracket, the top is bolted. Unplug the power, unbolt the top bolts, tip back and lift out. Be careful on to damage the radiator core when you're pulling them out. Might need to pull the top radiator hose or, move that fan over to clear it before lifting it out.

If they went to a single shroud or something like that, I havn't done it but I would think it's a similar deal.

[hiker88]

I wanted to update everyone as to how this turned out. I ordered a fan from gopartcom. Unfortunately, they sent me a driver's side fan, but I was able to switch the new motor into my currently assembly. The electrical connection was an exact match.

As soon as I started the car with AC on, I now have two fans. TADA!!

But a few questions more if you will indulge me.

I left the car running while I was cleaning up the garage etc. When I got in to go home, the interior was definately much much cooler than it had been recently (of course) but it wasn't what I would call great. However, as I drove it more yesterday things seemed to get better. We took a round trip drive of about 75 miles last night and I kept the AC on the whole way. On the way up I had the fan on full, recirculate and AC on. On the way home I turn the fan on to the lowest setting. We didn't really need AC but I wanted to keep using it. By the time we got home, the air was starting to feel quite cold.

When we got home last night, I got out the digital thermometer and did some comparisons with my Kia. Both cars are indicating about 40 psi at the low pressure port.

I tested with two different configurations for each car. One setting was the Subaru with the distributor switch on front vents only, fan on it's highest setting (4) AC on, and the recirculator button engaged. The comparable setting in the Kia was the distributor button on Max AC (this just turns on AC and recirculate on automatically from what I can tell) and the fan on highest setting (4).

In this configuration the compressors for both cars stay on continuously, the metal pipes at the low pressure port on the kia are incredibly cold to the touch, whereas the subaru is what I would called chilled. The air temparature at the vents for the Subaru was 52f and the kia 47.

The other setting is with the fan on the lowest setting (1) for both cars, the recirculate turn off and both cars sent to forward vents only.

This test surprised me. The compressors for both cars came on and off consistenly (the subaru being much much louder when disengaging). However, the tempartures for both cars dropped. The kia went down to 42f and the subaru came down to 47f.

I have two questions. Does it seem strange to anyone that the temperatures for both cars are actually colder when on the lower setting? Also, how do the temps I'm achieving with the Subaru sound? Are they as low as they should be?

Thanks again.

[wilsonhp]

Slower fan speeds generally achieve lower air temperatures as the air has more time to be cooled and de-humidified in contact with the fins in the evaporator. You are giving more time for the heat transfer to occur at low speed vs high speed.

Your ultimate low temp in the car will depend on actual cooled air temp achievable by the system, among other variables. Lower system air temp => lower car cabin temp, although you will never get the cabin temp to meet the system temp as that would lead to icing up in the system once no heat is being added to the evaporator.