W201 190D 2.5 Heater Fan

[sidmon]

Can anyone put my mind at rest. I'm currently "fettling" a 1989 Mercedes 190D 2.5. I've noticed if you turn on the interior fan, then leave it on and take the key out of the ignition.....it stays on! I'm fairly sure other 190's I've sold have never done this.....can anyone confirm or deny?

Also does anyone know the bleed screw thread size for the front calipers? I'm thinking 8mm but can anyone confirm.

 

[wireman]

Your fan should not run without the ignition switch being on at least the first on position.
The haynes book for all its inadequacies has sufficient detals on the heater fan in its wiring diagrams.

At 20 years old I would be fitting new bleed nipples the old ones may be sized in or starting to rot badly making for future trouble, you are right at 8mm. I replaced mine on a 190 and found the old nipples to be a shade longer in the thread (about 6mm ish) than the ones from my local car shop, I had doubts as to their suitability but found that they did fit and seal but the hex was only just away from the caliper. There are more than one makers calipers fitted to 190 models so I respectfully suggest that you get replacements from MB quoting your VIN to be sure of getting the right part.

If the brakes have been untouched for years and the bleed nipples are reluctant to move do not try too much brute force or their heads may snap off, try a sharp blow end on with a light hammer to crack the rust before you pull at them with any significant force.
If on having done this and the flats are a wee shade faded preventing the use of a decent spanner only resort to mole/vice grips with a close fitting small rod or bar (drill shank?) inserted deep into the bleed hole to prevent squashing the nipple flat and making it a dockyard job to extract them.

 

[television]

The heater fan should not run with the key out,,,it could be the ignition switch at fault

 

[star]

The heater fan should not run with the key out,,,it could be the ignition switch at fault

as above or the comfort circuit is at fault, do the windows work with doors shut and ign off?