Pontiac Montana Heater Fan not blowing at low settings

[ExtremeSi]

So my dad's 2001 Pontiac Montana minivan's heater is not working properly. There are 5 settings for fan speed and it only works on setting 4 and 5. Settings 1-3 don't do anything. Does anyone know what could cause this? I was hoping to narrow down the possibilities before replacing parts.

Thanks!

[dj_rice]

On most Nissan vehicles, if that happens, its always the heater resistor/power module/electric resistance part that is replaced. I don't know if this would be the same case with a Pontiac

[ExtremeSi]

Originally posted by dj_rice
On most Nissan vehicles, if that happens, its always the heater resistor/power module/electric resistance part that is replaced. I don't know if this would be the same case with a Pontiac

Cool, is that usually in the actual climate control unit itself (the interior piece with the knobs on it)?

[brucebanner]

Originally posted by ExtremeSi


Cool, is that usually in the actual climate control unit itself (the interior piece with the knobs on it)?

99% Heater resistor is what you want to replace. Common problem with GMs and no it is not the climate control unit. If I'm not mistaken the resistor is located under the dash on the passenger side.

[TomcoPDR]

I think on these, the resistor's in the motor assembly... Common on the GM's.

[EM1FTW]

blower motor resistor for sure. it bolts into the blower motor itself IIRC

[ExtremeSi]

Great, good to know guys. I hope the resistor is an easy-to-get-to part. Anyone know what it looks like? I'm guessing a little black box attached to the blower motor? I'm not at my dad's house right now so I can't check.

[AE92_TreunoSC]

Ya its a small black brick that bolts into the blower motor housing with a electrical connector going to it.

I've changed a hundred on chevys and its very likely the problem.

[Muji]

Originally posted by AE92_TreunoSC
Ya its a small black brick that bolts into the blower motor housing with a electrical connector going to it.

I've changed a hundred on chevys and its very likely the problem.

Just wondering, any risk of the OP losing heater settings 4/5 in time? Does he need to get this fixed right away or does he have a couple of weeks?

[AE92_TreunoSC]

max speed usually runs a seperate circuit and often a relay for the high current, so he will always retain max.

Usually the low speeds go first, as its a stepped resistance that starts from high (low speed) to low (near max speed).

The problem is usually the blow motor dies with a bad resistor. No idea why, but quite often, a week after changing the fried resistor, I have to change the blower motor.

So we try to change them in pairs if the budget allows for it.

But often if the resistor fries they'll credit the warranty but only if you change the motor with it.

[Muji]

Originally posted by AE92_TreunoSC
max speed usually runs a seperate circuit and often a relay for the high current, so he will always retain max.

Usually the low speeds go first, as its a stepped resistance that starts from high (low speed) to low (near max speed).

The problem is usually the blow motor dies with a bad resistor. No idea why, but quite often, a week after changing the fried resistor, I have to change the blower motor.

So we try to change them in pairs if the budget allows for it.

But often if the resistor fries they'll credit the warranty but only if you change the motor with it.

Thanks for the walkthrough, so often when one thing needs to be replaced we need to replace another "while we are in there". Better to know the full story and save some labour costs and worse get screwed in -25 degree weather, 300 miles from home with no heater.

[ExtremeSi]

Thanks. I'll change the resistor out and hope that the blower motor doesn't go too.