w123 heat only works when i turn key?
 

My heat only works in my 85 euro 300D when I start car and turn on heat then move my ignition key - just a tad to the left. Has anyone encountered this? What is the fix?

You need to replace the electrical portion of your ignition switch. Very common problem i have seen it a lot.

thx - very helpful

never did get around to doing anything - then yesterday I met a guy test drive it (after I drove it and met him) and he kept turning key and now it goes all the way to the right and nothing happens. I am going up there this morning and making sure battery is fine and lites come on - and will see if glow plug lite will come on. My son says AAA will come out and do some repairs if I know exactly what to tell them.

I had this problem with my 87 300TD.

There are three parts to the "ignition" switch:

1. Lock barrel. This is the part the key fits
2. Flat connecting rod. This part joins part #1 with part #3.
3. Electrical switch. This part contains the contacts and a rotary arm that moves in concert with part #1, via part #2.

On my car, part #2 failed. It twisted, and did not allow the rotary arm in part #3 to make contact with the starter terminal.

For simplicity, I'm disregarding the steering column lock mechanism.....:)

Jim

Cleaning the copper contacts on the back of the ignition AND slightly pulling FWD the tabs to add more tension is a fix if you don't want to throw cash at a new one.