Low speed ac fan relay

[jerbo1978]

2012 Ram 1500 electric auxiliary fan(AC condenser fan) won't turn on when low speed relay is bypassed in TIPM.
Anyone have any ideas why?

 

[Dean2]

Does it run on high. If not likely the fan motor is not working. Are you running a hot lead right to the fan, if not it could also be the wiring between the TIPM and the fan. Could be the connector at the fan also.

 

[jerbo1978]

Does it run on high. If not likely the fan motor is not working. Are you running a hot lead right to the fan, if not it could also be the wiring between the TIPM and the fan. Could be the connector at the fan also.

If I jump the high relay, which is on the horn bracket,the fan comes on.
The Electric fan is a Danco fan...I'm not sure if it's the original one or not.
The fan shroud actually has a cutout in it...the cutout looks like it was for the fan resistor

 

[FabricGATOR]

Computers

We have to be careful jumping stuff out in the relay and tipm now a day
It could result in blowing out the PCM driver that actuates that relay.

You can certainly simulate a closed or open relay by closing or opening the circuit to 87 / 87a but be careful around the control pins on the relay. Sometimes the computer (module, PCM, BCM, control head) applies power to actuate the relay and other times the module provides the ground path.


I hope this helps you.

Please return and tell how this information worked for you, what you find, and how you eventually fix your vehicle (even if it is that you brought it to a mechanic / dealership for repair)
It is your feedback and final repair report that will make these forums useful to others in the future.
Many times I search and find the same exact fault that I am having, someone suggests how to fix it, the patron follows the suggestion and then never returns to say YEA! or NAY...


The forum thread just goes dead because the person fixed their fault and has not a care to offer the answer anymore. Please don't be that guy.

Cheers!

 

[jerbo1978]

Computers

We have to be careful jumping stuff out in the relay and tipm now a day
It could result in blowing out the PCM driver that actuates that relay.

You can certainly simulate a closed or open relay by closing or opening the circuit to 87 / 87a but be careful around the control pins on the relay. Sometimes the computer (module, PCM, BCM, control head) applies power to actuate the relay and other times the module provides the ground path.


I hope this helps you.

Please return and tell how this information worked for you, what you find, and how you eventually fix your vehicle (even if it is that you brought it to a mechanic / dealership for repair)
It is your feedback and final repair report that will make these forums useful to others in the future.
Many times I search and find the same exact fault that I am having, someone suggests how to fix it, the patron follows the suggestion and then never returns to say YEA! or NAY...


The forum thread just goes dead because the person fixed their fault and has not a care to offer the answer anymore. Please don't be that guy.

Cheers!

Thank you

 

[jerbo1978]

Computers

We have to be careful jumping stuff out in the relay and tipm now a day
It could result in blowing out the PCM driver that actuates that relay.

You can certainly simulate a closed or open relay by closing or opening the circuit to 87 / 87a but be careful around the control pins on the relay. Sometimes the computer (module, PCM, BCM, control head) applies power to actuate the relay and other times the module provides the ground path.


I hope this helps you.

Please return and tell how this information worked for you, what you find, and how you eventually fix your vehicle (even if it is that you brought it to a mechanic / dealership for repair)
It is your feedback and final repair report that will make these forums useful to others in the future.
Many times I search and find the same exact fault that I am having, someone suggests how to fix it, the patron follows the suggestion and then never returns to say YEA! or NAY...


The forum thread just goes dead because the person fixed their fault and has not a care to offer the answer anymore. Please don't be that guy.

Cheers!

Just got back from a 2 hour and 2 hour back fishing trip, to prince gallitzin with my son.
The AC worked on the way up,without the Electric fan and the outside temp was 74...on the way home it was 84 and the AC was blowing warm air.
Pulled into the driveway and turned it on and off and heard a whoosh.
The compressor released freon

 

[FabricGATOR]

Hmm, there may be a safety pop off on the compressor. I know some do have it, not sure if all do though, if ours's does...
Is it possible that your A/C system was overcharged?

If overcharged, it can certainly blow warm. This whole black magic is based on the difference in pressure, and thus, change of state. If you have too much refrigerant there is not enough room for the liquid refrigerant to gas off.

Sorry, different 'client'

But, yes, hopefully there was a safety pop off valve that released high pressure VS something in the system popped!

So when rolling along and cool air was flowing into the hood, the air got cool in the morning. Afternoon, not so much.
Many times I hear that the a/c quits when at a stop light or parked idling. In most conventional set ups that indicates the electric fan is not running but then the AC gets cool because forward motion removes heat from up front.

A/c is like a bilge pump. you are pumping heat overboard. without the fan pulling air, the systems efficiency is limited to what you give it by forward motion and temperature offset. Obviously cooler air can absorb more heat that afternoon warmer air.

 

[jerbo1978]

That makes sense, maybe the Ac pressure switch is preventing the condenser fan from turning on ?
Or Pcm need reprogrammed ?

 

[FabricGATOR]

Hey jerbo1978, the guys in the 4th gen RAM forum may be better able to help you over there. This 3rd gen is 02-08 and your a 12
Not that I (we) are giving up on you, rather this may be a 4th generation common fault that the guys can tell you to 'wrap a wet sock' around something or such...
They might be able to say right away.

 

[jerbo1978]

I thought this was the general forum not gen specific

 

[jerbo1978]

Hey jerbo1978, the guys in the 4th gen RAM forum may be better able to help you over there. This 3rd gen is 02-08 and your a 12
Not that I (we) are giving up on you, rather this may be a 4th generation common fault that the guys can tell you to 'wrap a wet sock' around something or such...
They might be able to say right away.

I have posted on 4th gen also..one guy told me to trace back wiring and look for corrosion which I did