Troubleshooting HVAC

Hello everyone lately I’ve been having trouble with my heat and ac only working on high and barley working on high, the blower motor sounds like it’s starts losing power. Almost like it’s shorting out but it doesn’t ever cut off completely and it constantly does it.

here’s the catch. I’ve replaced the blower motor resistor & the plug, the blower motor it’s self, the blower motor relay, and now I’ve replaced the the HVAC control ($160) and still nothing has changed at this point I’m tired of throwing parts at it. Could it possibly be the harness it’s self? It’s the beginning of winter here in Colorado & as a construction worker I do love my heat & ac in these conditions, any help would be appreciated thank you.

2013 2.7 TSS 2WD

 

You may want to check connector IA4 Pin 8 (Black/Yellow) behind the left kick panel.

 

Have you replaced both connectors/pigtails? The one that goes into the resistor, and the one that goes into the motor? I chased my tail intermittently for a couple years with the blower. After changing the resistor pack the second time and replacing that (burnt up) pigtail with a beefier betterer one, the blower would still occasionally lose power or cut out completely. Reseating the resistor connector would usually bring it back for an unknown amount of time.

Came to find out... it was actually the connector for the blower itself that was burning up, and I guess fiddling with the nearby resistor harness jostled the blower connector enough to restore some contact with the pins. It was quite crispy when I finally replaced it, after not having heat/defrost capabilities on the first cold day this winter. Tried to reseat it just to get me to work, but the burning plastic smell dissuaded me from messing with it anymore. Replaced that pigtail on my lunch break that day lol.

 

interesting. I changed mine out about a year ago along with the actual HVAC panel as it had burned up on both ends. Worked for about a year then tanked again. I will have to take a look at the motor connector. Right now I have 0 or all in blower speeds. Seems like some air is blowing all the time regardless of setting but super low.

 

Yes I’ve replaced both and still the same

 

was your HVAC panel burnt out behind where it plugs in? Mine was super burnt there which I replaced. Got one for steal on Ebay.

 

Power from the HEATER Relay to the blower motor goes through there.

 

That’s just the natural airflow as the vehicle is moving. The intake is right under the hood cowl where ambient air pressure is higher. The cab vents in the rear are in low pressure between the cab and bed. So air will always flow when recirc isn’t on. I’m sure convection helps it a bit too.

 

Nope it wasn’t burnt out either & I bought another panel and still didn’t work. So if someone needed a panel I have one lol

 

Okay thanks I will check, would you happen to have a diagram for the harness?

 

Which harness?

 

The blower motor

 

The wiring diagram is posted above.
I'd check Connector IA4 first like I said above.