A/C Condenser Fan Turning On Randomly

[grpht03ram]

I noticed the fan turns on when the HVAC system is off

it only seems to happen when engine coolant temps are ~220

Is this programmed in the computer to help engine cooling? I don't even think that fan can help with engine cooling.

I have a 2003 with the 4.7L with the stock mechanical fan.

Thanks

EDIT: i swapped relays. Fan still turned on

 

[Sherman Bird]

Relay contron runs to the PCM... so something odd is going on... Fins a shop to diagnose it!

 

[Snake15eyes1998]

The ac fan has nothing to do with engine cooling on our trucks.

 

[crash68]

Even if the AC condenser fan doesn't draw air through the radiator, it possible that it's turned on to help lower under hood temperatures. The OP does say it happens when the coolant is around 220°F.

 

[HemiLonestar]

Should only be one electric fan on the A/C condenser. It wouldn't do any good for the engine anyway. When you say HVAC off, do you mean the whole actual system (fan off, nothing lit up) or do you mean just the A/C portion? Is it on defrost at any point with any fan setting on?

 

[grpht03ram]

Even if the AC condenser fan doesn't draw air through the radiator, it possible that it's turned on to help lower under hood temperatures. The OP does say it happens when the coolant is around 220°F.

Could be, but i've never found anything concrete that says the 3G Rams are programmed for that

I just found an old thread here where someone had the same problem; a new fan motor fixed it. Could it a bad connection at the fan motor?

Like sherman said, I was thinking a bad connection somewhere in the fuse/relay PDC box or the PCM

 

[grpht03ram]

I found a few instances online of residential AC units that had the condenser fan running constantly

The solution was to replace the fan! Those fans had some sort of short inside the motor

I'm going to give that a shot and see if it works. The motor is available for purchase separately

 

[grpht03ram]

Update: A new fan motor fixed the problem

I installed the Four Seasons, part # 35077
I read bad reviews of the other aftermarket fan motors, mainly fitment problems

The 4 Seasons is made in Canada. Seemed very good quality and the fitment was perfect


EDIT: Some more info in case anyone has this problem:


I previously thought the fan came on with high coolant temps

After some troubleshooting I realized the fan would pretty much come on whenever it wanted
Darn near anytime the engine had been running for more than a few minutes, the fan turned on
Then it would keep running until the engine was shut off
If I turned the engine back on within a few minutes, the fan would continue running immediately

If the fan was off and I turned on the AC, the fan would turn on as it should, but then if I turned the AC off the fan would continue running indefinitely until the engine was shut off

With new fan motor installed, I turned on the AC, the condenser fan came on, I let the AC run for a few minutes, then I turned the AC off and the condenser fan shut off with 1-2 minutes as it should

I let the truck idle for a long while, the condenser fan never turned on

Im calling it case closed. I'll go for a test drive soon and verify