Heater fan is not working on1983 500 SL

[nh500sl]

I have the above issue. Where should I start. Is there a relay to check? I was looking in the fuse block and notice that the fuse for the aux fan looks as though it has been hot. Wouldn’t that be for engine cooling fan? Thanks for any information. Nick.

[Diseasel300]

The fan is extremely flaky on my SL. The culprit in my case is the pushbutton unit. If you push around on enough buttons for long enough, it'll kick on finally, then later crap out again. I've been too lazy to pull the unit and clean the contact and resolder the circuit board.

The Aux fan is the electric cooling fan in front of the radiator. If you still have the old aluminum fuses, hit the trash with them and replace with brass or copper. The aluminum ones degrade and contribute to lots of strange problems due to poor connections.

[nh500sl]

Thanks. I went to move the car. Upon starting it the fan came in for a second then off. I wiggles the key backnjust slightly and it came to life. Sounds like a problem with the ignition switch. Thanks for the information on the fuses.

[Diseasel300]

If wiggling the key got the fan to come on, time for a new electrical part of the switch. It has a contact that controls the fan circuit.

[nh500sl]

Hopefully it won’t be as much fun as my 1983 633CSI to change out.

[rowdie]

For me the hardest part was removing the steering wheel. Make sure the steering is unlocked.

A while you are there. If you haven't already replaced the odometer gears now is a good time. They will fail.

[nh500sl]

Is there a write up for this procedure? Thanks.

[rowdie]

Yes https://www.benzworld.org/forums/r-c107-sl-slc-class/1495136-steering-wheel-removal-odometer-repair-tutorial.html

[BWhitmore]

I have removed the instrument cluster on a number of W123 cars without the need to remove the steering wheel.

[okyoureabeast]

Originally Posted by BWhitmore

I have removed the instrument cluster on a number of W123 cars without the need to remove the steering wheel.

With all due respect, the r107 platform is familiar enough to be comfortable for a seasoned w123 owner, yet different enough to greatly annoy.

In this instance, if you sit in the cabin of any era r107 for any amount of time, you'll quickly realize that the steering wheel is a lot closer to the instrument cluster than a w123 is. It is impossible to remove the cluster without removing the wheel.

Source: Owned both and tried.