'86 300SDL Under-Dash Panel Removal - Passenger Side

I am trying to repair my heater blower motor and have gotten stuck in removing the under-dash panel passenger side. I removed the three screws at the top of the upholstery panel and there is also a plastic rivet.

The panel did not come away freely after removing these screws and is apparently secured in other locations.

I cannot identify where the other points of attachment are located and need detailed instructions.

Does the upholstery panel and the plastic panel below it come of as one piece, etc.

Thanks

Reply to
eddie
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Yes they can but they do come apart.

Reply to
Richard Sexton

Reply to
marlinspike

Thanks all for the help. Problem fixed. Service manual instructions were "incomplete".

Reply to
eddie

Yeah true, but it's nice to clean the upholsetry while it's off. It can get pretty dusty under there.

There's a balck plastic shield or cover that is between you and the blower motor. It is held in place by 3 or 4 philips screws AND has some plastic tabs that lock it into place at the rear of the upholstery piece. That might be what's messing you up it got me the first time.

If you're still stuck I can send pics as mine is aaprt right now for cleaning anyway.

Reply to
Richard Sexton

Thanks for all the help. I was finally able to pull the heater blower motor with the intent of replacing the brushes. Before repairing the motor, however, I applied 12Vdc directly and the motor works fine.

The motor therefore was not the problem with the blower fan not working. Next to the motor is a finned aluminum "heat exchanger" with three input wires out to a plug and a red and blue wire going to the motor.

I suspect that there is an over temperature sensor on the "heat exchanger" that may have failed in the open position because I do not get continuity across this unit from the blue motor wire to any pin on the plug.

I do get continuity from a pin on the plug to the red motor lead.

3-Wire Plug -> Finned Aluminun Heat Exchanger -> (Red & Blue Wire) ->

Motor

Can anyone confirm that there is a normally closed (NC) overtemperature contact on the Finned Aluminun Heat Exchanger?

(Since I have voltage on the female end of the plug I do not believe that the pushbuttons are an issue. Any other trouble shooting tips will be appreciated.)

Anyone with a circuit schematic?

Thanks

Reply to
eddie

Ok, BTDT. There's all sorts of bits and pieces to maknig thr automatic climate control work. But, the one that fails 99% of the time IMO is the climate control pushbutton assembly.

It's where all the logic is to drive the whole system. There's

5 or 6 relays on there packed between two curcuit boards that get too hot; traces sometimes vaporize off the board.

You need to get a new one of these although new is perhaps the wrong word as they're bicg bucks new. You can usually get one off ebay for about $50.

When/why did it stop working? Blowing any fuses? Upgrade the stereo?

Reply to
Richard Sexton

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