MIL light not illuminating...

[Tech2Zero]

Hi All, I've been loitering for some time on here, but first post today!
My '58 CLS 350 CGI just went to the local dealer for an MOT, service and a full Command update.

It failed the MOT on a lot of things - control arms, ball joints, corroded brake pipes and hoses, a cracked wheel and a non-functioniong MIL light...
Its the MIL light issue that is most worrying. Apparently its doesn't illuminate during the initial 'ignition on' test. The dealer has told me its either a faulty clock/instrument panel or its the ECU and either will be an expensive fix (4 figures).

I work it IT so Im well versed in logical troubleshooting and problem solving so my first thought is to check the bulb. Can anyone confirm if there are bulbs behind the clocks, or are they PCB mounted LEDs? Has anyone come across this issue or similar. Searching here and google offered little insight. I've searched for MIL, CEL, and their non-abbrieviated equivalents but all results refer to the light coming on.

Thanks in advance...

 

[alecmascot]

I had this issue on my W203. I stripped the cluster and found only surface mounted LEDs. The LED itself was ok so I got a used cluster from eBay, had the mileage corrected to near zero and has it coded by a local indy. The panel will work without coding but will not show the mileage.
Make sure the cluster p/n match.

Edit. There are outfits who will repair, but they seemed expensive to me.

 

[Tech2Zero]

I had this issue on my W203. I stripped the cluster and found only surface mounted LEDs. The LED itself was ok so I got a used cluster from eBay, had the mileage corrected to near zero and has it coded by a local indy. The panel will work without coding but will not show the mileage.
Make sure the cluster p/n match.

Edit. There are outfits who will repair, but they seemed expensive to me.

Thanks for the info. I wasn't sure if indy's could do that sort of work so thanks for confirming.
I think I'll take your route and remove the clocks and see whats there...

 

[alecmascot]

Thanks for the info. I wasn't sure if indy's could do that sort of work so thanks for confirming.
I think I'll take your route and remove the clocks and see whats there...

There may be a bit of tape....