Intermittent A/C Blower Failure

[local]

I have never had any issues with the A/C in the 6 months I have owned my truck. Today I had a two hour round trip and on the way there the A/C suddenly just stopped blowing completely. After about 5 minutes it kicked back on. On the way back it didn't start blowing until a few minutes into my drive. I tried to control it manually and it was unresponsive. Once it came back on everything worked as expected. But it proceeded to do this cutout 4 more times on the hour drive. I need to get this figured out before it gets to 100 outside in a couple weeks.

7 speed A/C
Running in Auto randomly stops blowing.
Manual mode unresponsive until it comes back on a few minutes later.

Any ideas?

 

[local]

Apparently not. The problem is getting worse, much worse. I am going to try replacing the part they call a resistor even though I don't think these kind of systems use real resistors. If that doesn't work I may get desperate enough to wire up a direct connection for full power until I can figure out what is going on here. I don't think it is the motor as when it works it works fine so I am assuming it must be power related.

 

[local]

Well that did nothing, blower cut out within 1 minute. After that I did find that thumping the blower relay would get it working for a minute. So I took it out and smacked the hell out of it. Still cut out. Tried to find a new one, apparently this is one of the rarest relays on the planet. So I gave up and swapped relays for something called EBL, google says that is the rear window defroster but I don't have one so shouldn't be any big loss. It ran for a few minutes so I will find out tomorrow if it works. In the meantime I found an OEM relay on eBay for $16 so I bought that.

 

[local]

And fail again, second relay does basically the same thing. Since tapping the relay fixes it that means it should be in the connections for that relay. When it is out I will turn the fan on manual and notice every once in a while I get a little air pulse. Hitting a sufficiently large bump seems to also fix it most of the time. However hitting a bump while it is running does not turn it off.

 

[local]

Crap.

 

[local]

Not much I can do about this unless I want to try an find a new connector and then splice a ton of wires together or completely rewire the blower independent of the power center. Neither of those options are particularly appealing to me so I cleaned and bent the contacts then jammed a ton of dielectric grease into the port. Reassembled and it is working for now. Going to get it to a dealer to come up with an actual fix. If the repair ends up burning down the truck I want it to be someone else's repair not mine.

 

[Planejerry]

It sounds like a common blower motor issue. I would get a new one, not that expensive and very easy to install.

 

[local]

It sounds like a common blower motor issue. I would get a new one, not that expensive and very easy to install.

It has nothing to do with the blower motor. The pin coming out of the TIPM for the blower has been arcing inside the connector causing it to short and partially melt the connector. I made a shade tree mechanic fix to try and stop the arcing but I do not know why it started in the first place. If the problem is due to something in the TIPM I might be screwed, these aren't exactly sitting on the shelf. The connector appears to be part of the wiring harness and I could not locate one by itself. If the problem is in the TIPM or if my temp fix fails I could easily start a fire under the hood and burn down the truck.



I guess technically this isn't a specifically interior problem anymore but I have no idea where to put this and I could really use some suggestions here.

 

[Wild one]

It has nothing to do with the blower motor. The pin coming out of the TIPM for the blower has been arcing inside the connector causing it to short and partially melt the connector. I made a shade tree mechanic fix to try and stop the arcing but I do not know why it started in the first place. If the problem is due to something in the TIPM I might be screwed, these aren't exactly sitting on the shelf. The connector appears to be part of the wiring harness and I could not locate one by itself. If the problem is in the TIPM or if my temp fix fails I could easily start a fire under the hood and burn down the truck.



I guess technically this isn't a specifically interior problem anymore but I have no idea where to put this and I could really use some suggestions here.

If the blower motor has a high resistance on start-up,it can burn the electrical connector that feeds the motor.Try swapping the blower motor to.A high resistance caused that connection to get hot,and if that's the power feed to the blower motor,odds are the blower motor itself is your high resistance.

 

[local]

If the blower motor has a high resistance on start-up,it can burn the electrical connector that feeds the motor.Try swapping the blower motor to.A high resistance caused that connection to get hot,and if that's the power feed to the blower motor,odds are the blower motor itself is your high resistance.

That was a possibility until today. Dealer looked into that and the blower is actually running a bit under spec for amps. So now I am waiting on word on if warranty will cover the replacement of the connector. They should from what I am told but it has to be approved. If it comes back negative I will just wire in a separate relay and be done with it.

 

[local]

Surprise surprise, warranty is not going to cover the connector. Doesn't cover electrical connectors they say. So that leaves me two options:

1. Get the replacement connector with pigtail from the dealer for about $40 and splice the 20 some odd wires together myself, not paying the dealer $450 to splice some wires.

2. Go the way I was planning before finding an actual connector and bypassing the TIPM for the blower motor entirely. It will cost about $60 in decent quality parts but will result in only one splice instead of a whole pile of them.

I am strongly leaning towards option #2 as it is the less intrusive fix and if that fails I can always do option #1.