Bad Blower Motor & Fuse #5 Popping on '97 850 GLT Sedan

[BenSteiner]

Hi all,

I have a '97 850 GLT sedan w/ roughly 127k miles & an ECC.

The other night, the blower motor started screeching all of a sudden. Shortly after the fan went on high by itself and continued to do the same thing for roughly 30 seconds even after turning the fan off & shutting the engine off. Following this, I restarted the car but found that the blower motor wouldn't engage and that the REC & A/C lights were now blinking.

Not knowing anything else to check, I killed the engine, took out the key and popped the hood. I opened the fuse box to find the #31 25A fuse (ECC / heater fan speed 1-3) intact, but the #5 30A fuse (heater fan speed 4) blown. I attempted to replace it, but it immediately blew. Cut to 3 fuses later - each having immediately popped upon insertion - and I figured I'd better start doing a little detective work. I can feel warm air coming out the vents when I get up to speed, but that's about it.

The only thing I can think of is that there's a short somewhere, but I have no idea otherwise. I don't have the tools or experience to make this a DIY fix so have made an appointment to have a local garage look at it this weekend, but would love to hear if anyone has any ideas so I can pass them on to my mechanic & make his job a bit easier.

Thanks in advance!



Ben

[Ozark Lee]

The blower motor has shorted out and chances are that it took the power stage "blower resistor" with it. Change the blower first and chances are it will come back on at full speed and be uncontrollable. That is a sure sign that the power stage has shorted out. Another failure mode is that the blower won't come on at all. If either of those likely things happens the power stage will need to be replaced as well as the blower.

Don't try a new power stage first since a shorted out blower will destroy the new one. A bad power stage won't hurt the new blower though so long as you pull the fuse again to shut it off.

...Lee

[BEJinFbk]

I think you're mixing up ECC and MCC, Lee. OP states that he has 4 speeds.

Ben - ECC is the Electronic version with a variable speed fan control and
an AUTO mode, while the MCC is Manual, with a 4 speed fan slider switch.

Motor sounds like it's toast and it may have taken the speed switch with it.
Now the Speed 4 direct power relay is "stuck" on. Just guessing, though.

In Speed 4, the system energizes a direct power relay that bypasses the
duct mounted resistor pack that varies the motor voltage for speeds 1-3.

It should be safe to replace the motor and get some "full blast" heat,
but I'd probably start by inspecting the resistor pack ( made up of actual
resistors! ) and the fan speed switch contacts. It may be a little melty...

[BenSteiner]

Thanks for the advice, guys. I mentioned the blower resistor to my mechanic and he's checking it now while I have a bagel & coffee.

BTW, I do indeed have an ECC and not the MCC. The fan speed is gradual & the temp selectors for passenger & driver sides have Fahrenheit gradations. The fusebox cover mentions heater speed 4, but there's nothing on the unit itself about any specific speeds.

Cheers!



Ben

[BenSteiner]

UPDATE @ 1315 on 28 Jan:

The mechanic confirmed that I need a new blower motor & blower motor resistor & quoted me a price of $249.99 & $205.99, respectively, with the caveat that it would take 4-5 days to get the parts once ordered.

Question #1: Is this a decent price?
Question #2: I'll be out of town for the next week & am in no hurry, so if anyone knows of a better price / place to buy online, please let me know.

Thanks!



Ben

[angelglo]

Ben,

Unless you really cant do the job yourself, I would buy a blower motor like this. $58.30 for the motor. They sit right behind the glove compartment which is only held on by a few screws. I thing the blower itself is only held on my about 3 or 4 screws and has a connector. a fairly simple and basic job. It should only take you about an hour.

http://www.ebay.com/itm/New-Blower-Moto ... -c&vxp=mtr