Audi 100, '94. no heat

[msh]

Originally Posted by The Real MSH!

Cheers

I've measured the supply to the motor. Never changes from 5v. I'm hoping to drive it manually to see if it's the motor or the controller.

Most likely motor. The supply you've measured most likely is for potentiometer, not motor.

[Hanuman]

Originally Posted by msh

Most likely motor. The supply you've measured most likely is for potentiometer, not motor.

I think you are probably right.

Originally Posted by Gib

NO and No again don't try to drive these manually they are feed back motors and you will start to get into all kinds of pain if you do . Options are remove clean and reassemble which will sort most stuck motors or drop the arm of cable tie in position and do the above when its warmer.

Badly worded. My mistake. I meant I was going to try to drive the motor from a separate supply before removing it. However. I'm probably going with the option of lifting out the evaporator, instead.

So, once again, pics and guidance, much appreciated.

[msh]

If you have working AC, you might consider removing whole heater unit and leaving evaporator in place. This choice sometimes has to be done by LHD C4 owners when they have to change fan - sometimes they chose to cut out a piece of heater case which is obstructing and glue it back in place afterwards

[Gib]

AGAIN NO Rhd btdt

[Hanuman]

Woohoo. Heat. And still with aircon charged.

Method. (Being able to visualize and being flexible helps. As does having small hands that fit in tight places and make girls smile!)


Plastic rain tray off- metal clips
Wipers off. Nut covers pry off, 13mm nuts
Metal grill trim off- allen head screws. 4x
Plastic trim under neath off.
Support bracket for the metal off- 2x 10mm nuts

Now you can get at the motor cover. It has 5 self tappers. 3 are easy to access wih a cross head bit and ratchet. The 2 underneath are a sod, as the bit that I had was just too long. Cut it down is one option. (Un)Fortunately, the rear most is also on a post and the post is brittle. So a bit of torque on the screw snapped off the post. One screw to go, which I could just get to with my 90degree cross head screw driver.

I chose then to take out the cross head self tapper screw that secures the arm to the shaft.

3x self tapper screws hold the motor on.

This is the motor from the 100. I've also used pretty much the same method to remove the motor from the toad.


The motor from the toad was very dry inside, with a touch of verdigris on the worm drive. It also had some corrosion on the shaft for the middle gear.
The motor from the 100 was also very dry.

I decided to use some dry lube and see how that works.

2 motors removed, cleaned, and tested.
I also took the opportunity to remove a huge amount of rotting vegetation from the scuttle area and clean out the drains.

The V8 and 100 are very similar chassis. There is a drain against the right wing. There is also a drain just left of centre which drains into the engine bay. The latter being pretty much obscured ...here's a pic of approximately where it is....



Follow the red handle down

[msh]

C3 and C4 bodyshell apart from body shape differs mostly in mount points for various stuff. Physically there isn't problem to put C4 climate control in a C3, the main problem is that there are differences in AC component layout in engine compartment, forcing to keep C3 evaporator or make a lot of changes in engine compartment - but that's for LHD, I wouldn't be surprised if it turned out that RHD climate control would have no air flow flap in evaporator, which is the main difference. That temperature flap motor strangely is shared between C3 and C4 - one of few C3 climate control elements carried over. I hope you packed it with grease good enough and removed as much of gears as possible to allow grease to penetrate as much as possible.

Originally Posted by Gib

AGAIN NO Rhd btdt

No for what - possibility to remove heater while leaving AC intact?