Cooling fans for a/c

[Wilburnwalker]

My lacrosse a/c works great while car is moving. The cooling fans are not coming on while idling at a stop. I changed the relay and checked cooling fan fuses. They work sometimes but sometimes come on intermittently. How can I trouble shoot this. No codes show on scanner.
Thanks.

 

[MelsRegal]

My lacrosse a/c works great while car is moving. The cooling fans are not coming on while idling at a stop. I changed the relay and checked cooling fan fuses. They work sometimes but sometimes come on intermittently. How can I trouble shoot this. No codes show on scanner.
Thanks.

Does it overheat?

 

[richardnewton]

Maybe check the wiring to the fan for any damage. Inspect the connectors for damage. Inspect the contacts at the fuses & relays too.

Failing electric fans may not turn freely. They may also work intermittently where a few gentle taps or assistance to get spinning gets them going. Car fans are an easy way to lose fingers so you really don't want to be putting your hand near the fan with the battery connected.

Some fans can turn on anytime, even with the car off and key out of the ignition. Use extreme caution.

Oh, the AC condenser fan is really useful in traffic and city driving, but once the car is moving, fan becomes less critical. Incidentially, the AC fan may provide some airflow to the engine and transmission coolers too so you want that working ASAP with these temperatures.

 

[Wilburnwalker]

Maybe check the wiring to the fan for any damage. Inspect the connectors for damage. Inspect the contacts at the fuses & relays too.

Failing electric fans may not turn freely. They may also work intermittently where a few gentle taps or assistance to get spinning gets them going. Car fans are an easy way to lose fingers so you really don't want to be putting your hand near the fan with the battery connected.

Some fans can turn on anytime, even with the car off and key out of the ignition. Use extreme caution.

Oh, the AC condenser fan is really useful in traffic and city driving, but once the car is moving, fan becomes less critical. Incidentially, the AC fan may provide some airflow to the engine and transmission coolers too so you want that working ASAP with these temperatures.

The car is not running hot. It is somehow connected with the A/C switch turning the fans on. Should always come on when A/C is on, right? Relay had a black burned spot on it so I bought a new one and replaced it. Still doing it.

 

[MelsRegal]

Is the compressor running when the fans aren't running.
Not sure if you have a real problem or the compressor isnt running at times causing the fan not to run.

 

[Wilburnwalker]

Is the compressor running when the fans aren't running.
Not sure if you have a real problem or the compressor isnt running at times causing the fan not to run.

Yes the compressor is running all the time the A/C switch is on but when the fans are not running no air is flowing through the condensing coil. I turned the A/C switch off a few seconds and turned it back on this morning and it started cooling. The fans had come on. Since it is intermittent I thought the relay was sticking but the new relay did not help.

 

[richardnewton]

The car is not running hot. It is somehow connected with the A/C switch turning the fans on. Should always come on when A/C is on, right? Relay had a black burned spot on it so I bought a new one and replaced it. Still doing it.

On some GM cars, the AC compressor does not always turn on the related fan and there may be a delay in any case. I don't know about the LaCrosse.

The burn mark on the relay could be a tell-tale or a red herring.

 

[Wilburnwalker]

I’m back. I have changed the coolant temp sensor and nothing has changed. I start it up with the a/c on and the fans still don’t come on. Therefore, there is no cooling while the car is sitting still. If I drive it for a 1/2 mile or so, it cools. The fans will come on at some point but I don’t know why. Maybe they come on when the temp of the engine reaches a certain point. So it looks like the a/c switch is not kicking the fans on during idle or….. maybe not ever. Any other ideas?

 

[MelsRegal]

Have it diagnosed at a shop that can actually connect to the ECM and see what readings it's getting from all sensors.

 

[Wilburnwalker]

No codes on the scanner so I guess that’s the only choice I have.

 

[oldcarowner]

No codes on the scanner so I guess that’s the only choice I have.

When the A/C is cooling what is the temperature of the air coming out of the vents?

 

[Wilburnwalker]

I haven’t checked with a thermometer but it is very cold. It works great while the car is moving.

 

[Wilburnwalker]

Ok. Question: Am I right in assuming that the cooling fans should be on when the a/c is on and the engine is cold and idling?

 

[HotZ28]

Ok. Question: Am I right in assuming that the cooling fans should be on when the a/c is on and the engine is cold and idling?

Yes, as long as the pressure switch is working & the pressure is above 185 psi, which is normal with a fully charged system. The low speed fan will only turn ON, if the PCM is getting the correct info from the pressure switch. Do you have 12v @ the fan with the AC on?

 

[Wilburnwalker]

I just went out and started the car. Cold engine. Compressor running but no voltage at fan. Waited and let it set running and the fans both came on after about 5 minutes. Once they came on it got cold inside. I have changed the pressure switch on the a/c line and the coolant temp sensor. I have changed the relay and checked fuses. Could over charging cause this?

 

[HotZ28]

I just went out and started the car. Cold engine. Compressor running but no voltage at fan. Waited and let it set running and the fans both came on after about 5 minutes. Once they came on it got cold inside. I have changed the pressure switch on the a/c line and the coolant temp sensor. I have changed the relay and checked fuses. Could over charging cause this?

Since the problem is intermittent and sometimes works if you turn OFF the AC and back ON again & the fan's work would indicate to me that there is a bad connection in the relay socket.

 

[Wilburnwalker]

That makes sense because the original relay had a burned look at one terminal. The new one looks fine so far. I will try wiggling the relay while running and see if the fans come on. I’ll let you know what happens. Thanks, again.

 

[-Regal-]

I grabbed three free Hella fuses at the junkyard yesterday. They all had what looked like a tinge of "burn" in the middle (I believe 87a) terminal. When I saw the first one I wasn't going to take them, but when I saw they were all like that realized it's either likely something with the manufacture of those particular fuses (or maybe the electrical system in that car had really been fried before it was taken off the road and those fuses are junk).

Perhaps you can swap around a couple of the fuses on the panel? I did that recently just to test things and since nothing changed just left it that way. The ones one my car still appear to be the factory fuses.

 

[Wilburnwalker]

Yes, I switched two that were identical in the beginning and it didn’t help but since one looked burned, I bought a new AC Delco and replaced the burned one. ????

 

[-Regal-]

Yes, I switched two that were identical in the beginning and it didn’t help but since one looked burned, I bought a new AC Delco and replaced the burned one. ????

Possibly the pins connecting to the fuse are loose but it doesn't seem likely unless it's been replaced an exorbitant number of times for some reason.