Hey Everyone,

I just purchased a 1983 300d turbo, and I fear I will be found frozen to death in it soon. For God's sake, help me!
The cooling system seems to be working fine, but the heat only turns itself on once in a blue moon. Then it turns off again after a few seconds of heat.
The few times that the heat works, are usually when in park, or running at low rpm. I don't know if that has anything to do with anything, but I thought I would add it.
Also, in case this has anything to do with the problem, due to the abundance of vacuum hose "things", I thought I would list some other things I am fixing, in case they are linked:

1. Dash has a light out.
2. Climate Control Console is also only lit up a fraction of the time. Usually is not lit.
3. Windshield Wiper Fluid is not spraying even while full.

Hello,

If you're lucky, it is just a bad/dirty electrical connection at the monovalve (do a search in fastlane for a pic). If you're not so lucky, it could just be the monovalve insert (same fastlane area; called "repair kit"). Easy to replace...just take it apart slowly, so you can tell the order in which everything goes back together. If you are not lucky at all, it could be something more sinister that I haven't had happen yet.
The lights not working on the control panel, is probably just a busted bulb. You can pull that out in the spring when your fingers aren't so frozen .
OH! Before you do anything, be sure to check all your fuses with a magnifying glass...hairline cracks are not uncommon.

Hope this helps...

-Larry

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Thanks for the reply. Will definitely check out what you specified.

There is a new twist. Now that I have had time to drive the vehicle in it's present state, I now know that when parked, slow, idling at low rpm's, the heat works fine. As soon as I get moving and pick up speed, I end up freezing my butt off.
Any ideas?

Just purchased a 1983 300SD with the similar problem... no heat or defrost period. Pulled cleaned and checked the monovalve, no luck, all OK. Have now removed the knee upholstery and plastic toe panels on both sides, but cannot even see the blower and motor yet, where can I go from here? Outside temp is -20C but I have a warm garage to work. Started to remove the dash switch panel to get a look at the heat control module, pulled all the switches except 4 way is still stubborn, quit for the day frustrated.

Anyone with bright solutions out there? Searched last night with no worthwhile results.

Car also has tranny problem, (not going up to 3rd) working on that also, replaced one of the 3/2 vacuum switches and replaced the broken plastic "paddle" on the second switch with no results.

Tranny did shift up only once by rev'ing up to 4000 rpm and releasing the peddle quickly.

I knew about the tranny when I bought, looks like a rebuild unless someone has other ideas.
Thanks

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The meek shall inherit the earth, the brave shall get the oceans

AutumnIron, search on ACC module. It might need a cleaning, or re-soldering. The monovalve fails open, so there should be hot water. The ACC controls the blower.

Richard, try searching on Bowden Cable and Kickdown Switch, either could be causing your shifting problem.

Best Regards,
Jim

Make sure the aspiration tube from the cabin temp sensor (in the little square louvered thing front and center on the dashboard) to the fan housing is intact. You can inspect i by removing the glove box insert. The plastic rivets that hold the box in are easily removed if you pull their center inserts out. There's a section of foam tubing that can crumble away.

The next step would be to reflow the solder joints in the pushbutton unit.

Another thing to check for: air leaks at the firewall. If the rubber seal at the steering column is torn, it can let in a lot of winter air at speed.
HTH
Russ

Thanks Jim H and Maki
I finally found the blower and motor, under and behind the glove box!!! Checked it on the workbench @12 V she spins like a charm and no noise!!. I will try your suggestions next. Now I have a window down that will not go back up, no end of irritating problems but I am learning fast and having fun!!!. Presently also trying to remove the console wood panel to examine and resolder/reflow the ACC board but 4 way switch is still holding me up. I presume the fan speed is controlled by voltage change somewhere, but where? Is it simply the high/low/auto switch?

Re: the tranny, OK I will try the Bowden Cable and Kickdown Switch next. Also plan to have the vacuum checked to look for possible leaks. Any other things before I have the tranny pulled? The old owner said he broke a tranny cooling line and ran her dry, repaired the line and new fluid but she would not switch up to 3rd. I knew this before I made the deal.
This SD has 186,000 miles, is in good shape new tires, shocks and battery, found her in NY and towed her back to PEI Canada, the trip cost more than the car. There are only 4 rust spots on the doors, she passed inspection with only replacement of 2 rear brake hoses.
Sorry AutumnIron, did not mean to take up your bandwidth.
Like you any help is appreciated.
Dick W

__________________
The meek shall inherit the earth, the brave shall get the oceans