Intermittent Heater...

[beerosaur]

Hi all,My girlfriend has a 1995 Q45 which I've made several repairs to thanks to the forum, so first of all thanks for all the help you didn't know you were giving me! LOL...

The latest problem is an intermittent A/C and heater. Apparently when she gets in the car lately, the heater will either work or not. The panel lights up, the fan indicator moves around to high or low..where ever you put it... but it's either dead, or it works fine. Air conditioner follows the same pattern of behaviour.

Ideas?

How did your smiley get a hold of my old oil ?

-= Beer


Modified by beerosaur at 8:24 AM 12/11/2009

[Q451990]

Welcome to NICO!

Do you mean the fan does not work? If so it's probably a bad fan motor. My Mom had an '88 Maxima that would do the same thing. The brushes in the fan motor were so worn that they would get cocked at an angle and not make contact correctly.

I would either replace the motor with a new OEM one from http://www.everythinginfiniti.com, or try to find an "old school" electrical motor rebuilder in your city. These guys are usually second or third generation businesses located on the bad edge of downtown that specialize in alternator, starter, and DC motor repair. If you have a "pull a part" style salvage yard in your area you could always try the cheap option and see if you get lucky. It all depends on how long your girlfriend plans on keeping the car.

Heath

[beerosaur]

Hi,Well, that's a tricky question because the fan works sometimes... I don't know if it's the fan motor or something in between the control panel and the fan motor. Seems like if the motor was bad, it would be down all the time? But I know that's not necessarily the case either. By the way, where is the fan motor located and how do you get to it? I also read something about a fan motor resistor? I don't know anything about that at all...

I'd love to take it to the old school rebuild shop! I don't want those guys to go out of business!

-= Beer

[Q451990]

zerothread/262029

Sound familiar?

The resistor failure will cause the fan to run wide open all the time. The fan can definitely fix itself...

Heath

[beerosaur]

That's exactly it! I don't know why I didn't stumble on that during the search process but thank you for not saying, "Search you Idiot!"

So am I right in assuming the resistor is probably good if it runs normal when it kicks on?

-= Beer

[Q451990]

So am I right in assuming the resistor is probably good if it runs normal when it kicks on?

Absolutely.

http://www.q45.org is a good resource for finding article links here.

Heath

[beerosaur]

Ok, took it all apart, took the motor apart and found nasty armature and worn brushes... 10 bucks for brushes at the electric store, cut wires, soldered, mod the fit by orbital sander to shorten the brushes...sanded the armature...it's back together. Going to go stick it in the car....

I had to buy a higher carbon content brush, so they're softer... I wonder how long they will last? LOL

-= Beer
Modified by beerosaur at 3:53 PM 12/11/2009

[beerosaur]

Holy crap! The heater and AC work now... but the car won't start???!!! W T F????

-= Beer

[beerosaur]

PHew! I got it...Thanks Heath for all your help! $10 and a couple of hours

Now I'll confess to my bonehead....I disconnected the ECM harness to get it out of the way... oops! Guess what I forgot to hook up when I put it all back together???

-= Beer

[Q-ZILLA]

Had this problem, blew the dirt out of the motor real good, reinstalled, worked like a champ! God this car amazes me. 238624 miles; original blower motor, amp and all... Still running fine...

[qship96]

Had this problem, blew the dirt out of the motor real good, reinstalled, worked like a champ! God this car amazes me. 238624 miles; original blower motor, amp and all... Still running fine...

Unless you are the original owner{or bought car with very low miles and only a few years old}, how do you know blower motor or amp has not been replaced at least once by a previous owner? Blower motor on Q generally dies by 150K or so.

[Q-ZILLA]

I've had the car since 42k miles, for the past 13 years. All the "dust" in the blower motor must be from the brushes, so I'm assuming I'll be replaceing it in the near future. If I'd known about it soner, I'd cleaned it out sooner. I'm guessing all that "dust" causes it to wear out faster. Check yours out. You have to take out the 2 screws on the back of the motor and remove the backplate. The amp looks really aged, so I ordered another earlier this am, for the "fun" of it. I noticed it blows out harder than it used to as well.

[qship96]

the brushes wear creating the dust- I dont think cleaning the fan blade or other parts will slow down the brush wear, - I replaced mine already, as it was working on and off...upon autopsy, you could see the brushes were worn down to the point they barely made any electrical contact.....same with fuel pump,brushes wear and rattle around in their holders,which causes the famous fuel pump noise or humming.

Excellent idea to take the 10 minutes and clean the face of the evaporator while motor is out with foaming coil cleaner and little soft brushes, you will be shocked at the matted layer of hair/dirt/leaf debris partially clogging the evaporator, restricting airflow across it and hindering cooling power of the A/C system!