A/C has a poltergeist

[jerjus]

Have a 2010 ram 5.7 with digital climate controls. Problem is, when I first start truck A/C comes on like normal for about 30 seconds, blower motor runs at high speed set on auto then seems like it shuts down, I can hear and feel the blower motor running at an extremely low speed. After about 5 minutes it kicks into full auto and runs full blast and is fine after that till the next restart.

 

[NJMOPAR]

Try leaving the control on 0 instead of Auto.
Also have a 2010 & I've never used Auto for climate control. Mine stays blasting cold on remote start.

 

[Sandevino]

The blower motor resister could be on the way out.

 

[jerjus]

Tried new resistor, no difference. still did the same thing. I like using the auto setting being the truck came equipped with it. I expect it to work as designed. Thanks but if anything else crosses your mind let me know, Would really appreciate the help.

 

[Sandevino]

I agree with it working as designed.

if you turn it off then back on then to auto it works for the drive cycle?

 

[jerjus]

No. After engine start.. once it shuts down after the 30 seconds, it doesn't matter what you do, it will not start working until 5 or 6 minutes go buy, it's like it's on a timer. Then the blower motor runs normal as so does the whole system.

 

[Sandevino]

To make sure I understand...

When it works, all works fine. Cold a/c, auto fan speed, etc...

When it doesn’t and the blower runs on high, is this because it’s hot and trying to cool? I know it’s summer, but are you parked outside, inside, is the truck hot hot inside?

When it fails, have you taken a voltage reading at the blower? I assume you haven’t, but would like to know the voltage getting to the blower. Is the compressor running when it fails? What voltage do you see at the compressor? Have you checked / changed / swapped the relay? Does anything else not work when the a/c stops working?

Remove the blower motor, check / clean the relay.

Does the vent fan work when the blower fails with the a/c on? It sounds silly, but turn off the a/c and see if the vent fresh air works.

 

[jerjus]

To make sure I understand...

When it works, all works fine. Cold a/c, auto fan speed, etc...

When it doesn’t and the blower runs on high, is this because it’s hot and trying to cool? I know it’s summer, but are you parked outside, inside, is the truck hot hot inside?

When it fails, have you taken a voltage reading at the blower? I assume you haven’t, but would like to know the voltage getting to the blower. Is the compressor running when it fails? What voltage do you see at the compressor? Have you checked / changed / swapped the relay? Does anything else not work when the a/c stops working?

Remove the blower motor, check / clean the relay.

Does the vent fan work when the blower fails with the a/c on? It sounds silly, but turn off the a/c and see if the vent fresh air works.

Yes, when it works all works normal. When it doesn't work right there is some real light cool air blowing through the vents, I hear a fan noise but very low. I'm driving for about 5 minutes and just like that it starts working like there's nothing wrong. I have checked the resistor and even tried a new one, same results. I have not taken readings at blower motor but I do believe the last time I looked the A/C pump was engaging. Nothing else is effected by the shut down. As long as I'm driving it's great, I even been letting it run as stupid as it is when I get gas so I don't have to shut it off. If I do shut it off it repeats the annoying thing again.

 

[Ramman2009]

Did you try blowing out or cleaning the blower motor? Mine wasn’t blowing as hard and when I removed mine it was packed with dust.

 

[jerjus]

Did you try blowing out or cleaning the blower motor? Mine wasn’t blowing as hard and when I removed mine it was packed with dust.

Thanks but definitely not a dust issue.

 

[grizzstang]

It is probably the switch itself.

The heater/cooling controls in the Jeeps fail all the time.

I need to replace the one in our 2013 Jeep Wrangler before winter.

I would see if you do indeed have the problem when it is not on auto as suggested in post #2.

 

[jerjus]

It is probably the switch itself.

The heater/cooling controls in the Jeeps fail all the time.

I need to replace the one in our 2013 Jeep Wrangler before winter.

I would see if you do indeed have the problem when it is not on auto as suggested in post #2.

That is what I was thinking, the climate control head unit is the cause or if this model year truck has a computer to operate the system.

 

[Jowillia]

I'm curious what you found to be the problem here. I have the same issue and you're the only person I've seen with the same issue. Any info share would be appreciated. Thx..