'89 560SL no start
 

Also posted in SL Forum

No spark.

So I went to the pull-a-part this morning & snagged a couple of Ign modules & a coil. Got them out of a 560SEL & a 420SEL, the only 2 on the lot. Numbers are not an exact match.

Swapped in the coil w/old module - no joy.

Swapped in a module & it starts right up. Joy.

Shut down right away & came in to post this.

How critical are module p/n's?

First, I do not know for sure but suspect the current module IS NOT original. P/N is BOSCH 0 227 400 695/MZB 0 410 545 67 32 (03), it has worked for years. I suspect it was a heat failure because the heat sink goo did not look to be making good contact; many ripples due, I think, to a missing hold-down bolt.

The unit I got out of the 560SEL is BOSCH 0 227 400 624/MZB 004 545 53 32.

The 420 SEL is a SIEMENS 5WK6 114/MZB 004 545 55 32.

So I figure the best match is the BOSCH unit from the 560SEL but am looking for trouble or just being overly cautious?

I see parts distributors list the BOSCH 0 227 400 695 (same # as the bad unit I just removed) as the replacement for all years/models of 560's & a BOSCH 0 227 400 693 as the replacement for a 420. So I surmise something is different (mappings maybe?) & I should avoid the module from the 420.

Would I be correct in assuming the different #'s (695 vs 624) from the 560SEL are just an older variant? Although I do not trust ebay, both are listed as 560SL replacements there.

Anyone want to chime in?

According to EPC, there are several number changes but 004 545 53 32 is one of them, so that one you installed should be the right one.

Thanks, it is in and showing no signs of rejection, the patient lives!

I need to look at the alternator waveforms to see if there are any spikes which could have killed the other. Do that tonight. Still think it was heat however.