Blower motor

[kbenz]

Dies down? Temp gets not as cold, or little to no airflow but can still hear the fan, or fan stops?

Air flow dies out.

 

[kbenz]

Maybe the system is slightly overcharged? Maybe it's just so good that you can't run it full blast all the time?

I turned it off and opened windows for last 30 minutes of my drive then tried again and still sucked.

 

[kbenz]

When I first start up it takes a bit for it to start blowing good too

 

[DougBoy66]

When I first start up it takes a bit for it to start blowing good too

Mine is that way, check the defrost vent for flow. Mine seems to take a bit to come out the dash vent until the vacuum builds up but it is blowing out the defrost until then. I need to replace that white colored vacuum hose that goes to the blend door by the firewall

 

[kbenz]

Might be a couple weeks before I drive it enough to act up. But I did fix the blower motor connector. That was one of them run what you brung things and I’ll fix it right this weekend things 2 years ago

 

[kbenz]

Mine is that way, check the defrost vent for flow. Mine seems to take a bit to come out the dash vent until the vacuum builds up but it is blowing out the defrost until then. I need to replace that white colored vacuum hose that goes to the blend door by the firewall

I’ll Check that next time I drive it

 

[jim x 3]

KB:

Listen to Greenie, your evaporator is freezing up.

You say that after AC is on for an hour, the accumulator (round thingy) and lines freeze (with frozen condensate) and your air flow dies out. Therefore your evaporator is also freezing up.

You can check the blower by running it on HI for an hour without AC. Your air flow won't die out. [Don't do this without the engine running, you'll run down your battery - the blower takes a good bit of power].

Your evaporator is a radiator (in reverse) in the air ducting downstream of the blower - it gets cold when the liquid refrigerant sent to it EVAPORATES. When it gets cold, it cools off the air going thru it. If it gets too cold, it freezes water out of your air stream, which plugs up the evaporator air flow (freezing it up). Then your air flow dies out. When you shut off AC, the ice thaws and drips out of a tube below the cab. If you shut off the truck or run without AC your AC function will return to normal when all of the ice melts away.

Your evaporator is getting too cold.

So you need to figure out why this is happening.

Regards,
Jim x 3

 

[Black dawg]

KB:

Listen to Greenie, your evaporator is freezing up.

You say that after AC is on for an hour, the accumulator (round thingy) and lines freeze (with frozen condensate) and your air flow dies out. Therefore your evaporator is also freezing up.

You can check the blower by running it on HI for an hour without AC. Your air flow won't die out. [Don't do this without the engine running, you'll run down your battery - the blower takes a good bit of power].

Your evaporator is a radiator (in reverse) in the air ducting downstream of the blower - it gets cold when the liquid refrigerant sent to it EVAPORATES. When it gets cold, it cools off the air going thru it. If it gets too cold, it freezes water out of your air stream, which plugs up the evaporator air flow (freezing it up). Then your air flow dies out. When you shut off AC, the ice thaws and drips out of a tube below the cab. If you shut off the truck or run without AC your AC function will return to normal when all of the ice melts away.

Your evaporator is getting too cold.

So you need to figure out why this is happening.

Regards,

Jim x 3

maybe my reading comprehension sucks right now, but I dont think we have been given good enough info to decide anything for sure.......

 

[Danielle]

Also check for rats! My truck sits a lot and I get nests everywhere. This year was a nest surrounding my blower motor resistor, but I believe it was rubbing on fan and fan would get too hot and kind of stop/slow to nothing after 20 min

Its also pretty easy to take fan out of HVAC box and run it where you can see it, so you can monitor if that connector gets super toasty, or you can see rodent nests in the box, or smell resistor or fan motor

Here's some rats, both welcome and unwelcome rats

 

[jim x 3]

maybe my reading comprehension sucks right now, but I dont think we have been given good enough info to decide anything for sure.......

Agreed, my proposal is only a hypothesis. Its up to KB to determine if it holds water. It would be easy enuf to check: a blower that doesn't die out without AC and an iced-up evaporator can be readily seen if the blower assembly is removed from the duct.

 

[kbenz]

Mine is that way, check the defrost vent for flow. Mine seems to take a bit to come out the dash vent until the vacuum builds up but it is blowing out the defrost until then. I need to replace that white colored vacuum hose that goes to the blend door by the firewall

That's exactly what it was. That vacuum plunger under the dash is slow. Then after an hour or so it's probably switching back. I finally drove it today but not long enough to have it mess up after driving a while

 

[IDIBRONCO]

Could that possibly mean low vacuum? It may be worth looking into.

 

[DougBoy66]

That's exactly what it was

Glad you are closing in on it. I would follow up with what @IDIBRONCO said too

 

[kbenz]

Could that possibly mean low vacuum? It may be worth looking into.

I wondered that too. I'm not having any brake booster issues though?
How would I go about diagnosing a vacuum issue?

 

[ihc1470]

Does the air flow switch when it acts up? You could put a gauge on the system and see what you have or connect a hand vacuum pump to the supply hose of the HVAC system and see if it holds vacuum.