Issue With A/c Electric Cooling Fans Under The Hood.

[914lps]

I am having a major issue with A/C electric cooling fans under the hood (A/C Condenser Fan Assembly). The twin electric fans that come on to help cool the A/C condenser are not working.

This issue came up when fixing a leak in the A/C system. On putting the fans back in place it was discovered that a bird was badly mangled in the fan on the right or passenger side. Due to this bird jamming that fan, the motor is dead. When given direct voltage the other fan (drivers or left side works).

To try to get my car on the road as we look for a replacement fan, we moved the drivers side fan to the right passenger side. As this is more inline to cool the condenser coils.

But when we turn the A/C on, the fan is not coming on. Does anyone know how to test this to find out if it is a bad connection, or is the brain that controls the fans messed up??

Do both fans have to be connected for the system to turn them on? Or can you cheat with only one fan for a short time?

A wiring diagram would be great. As we may have a grounding issue.

Also anyone know where to get a replacement fan or motor without going though Lexus?

[James Horning]

If this is a LS 400 there is a temp switch for the fans at the bottom of the radiator ( simplest fix) or this could become extremely complex, relays are in stages for the current load. Is the A/C compressor actually coming on ? If you go the cheap route find a set of LS fans from a salvage yard.reading the proper manual / year is very important, knowing how they are designed to work is very important to the diagnosis process.

[914lps]

Yes it is a 1991 LS 400, sorry I did not state that information, but I thought that is why it shows to the left under my name.

Yes compressor is coming on.

I know that that knowing is important. That is why I a asking here. Especially in reference to the schematic.

I do not understand the statement "temp switch for the fans at the bottom of the radiator ( simplest fix)..." are you saying that if I do something with this switch it is the easiest way to get them working no matter what? The system seems a lot more complicated them that. And I am noit asking about them coming on due to engine temp. But when A/C is on. As turning A/C on is supposed to force the fans on as long as A/C is on... Is it not???

I do appreciate your help, and I am sure you know what you are meaning to say, but unfortunately I do not know what you are trying to tell me. Specifics would be very helpful.

That is why I am posting here. I know in general it could be several things.

[lenore]

The cooling fan itself could be test if one fan is still working swap or (sorry I have a great deal of electronics background) jump the fan to 12volts and make sure it works...If it works then you have either a sensor, relay, or wiring issue.

[914lps]

I thank you for posting and trying to help.

I must apologize. Apparently I did a not so great job of posting in the first place.

So I will try to fix that.

When I posted:

"To try to get my car on the road as we look for a replacement fan, we
moved the drivers side fan to the right passenger side. As this is more
inline to cool the condenser coils."

I wanted to convey that in fact the "bad fan" was switched with the working fan. And we knew one fan was working and one was not, as we pulled both and bench tested with 12 volts. One worked one did not. The working fan was the one normally on the left or drivers side. However we put it back on the Passenger side, and the bad fan was left off the car. Leaving no fan on the drivers side.

So you stated:

"The cooling fan itself could be test if one fan is still working swap or (sorry I have a
great deal of electronics background) jump the fan to 12volts and make
sure it works...If it works then you have either a sensor, relay, or
wiring issue."

So we already did do what you recommended to see if the fan(s) were good or not before I posted the thread here.

We know the one fan in the car is good.

We do not know why it is not coming on. We knew at the time it could be a wiring issue (one of the reasons I asked about a wiring schematic), Sensor, switch, or computer issue. That is WHY I posted here.

I am looking for more How To trouble shoot information, beyond what we already knew and did before I posted here.

I apologize for somehow not making this clear when I started the thread.

[steve2006]

If you pm your email address I will send you the wiring diagrams.

There are 3 relays involved in fan motor control and combined these control the fan operation of both the cooling system and AC.

[914lps]

WOW, thank you! PM sent! Again Thank you.

[914lps]

Still looking for information like diagnoses procedures and wiring etc......

[914lps]

If you pm your email address I will send you the wiring diagrams.

There are 3 relays involved in fan motor control and combined these control the fan operation of both the cooling system and AC.

I wanted to post a great big

Thank You!

For the info you sent me!

[steve2006]

No problem glad to be able to help, have you got it sorted yet?

[lexus4141]

If you pm your email address I will send you the wiring diagrams.

There are 3 relays involved in fan motor control and combined these control the fan operation of both the cooling system and AC.

Hi just became a member and I too am having problems with my fans not turn on. I check the one on driver side it dead, the one on the left is working thinking of change the temp switch. But, sure could use the wiring diagram if available.

Rob.

Thanks