Fuel Pump Relay Miasma
 

My manual Euro 1988 300CE is running poorly and often won't start. I have replaced a number of ignition and electronic components to try to get it right or at least narrowed down -- plugs, cap, rotor, wires, OVP, CPS. I found a quirk in the part numbers for the fuel pump relays. The OEM original relay is part number 002 545 51 05. Any search for that number or a model or VIN search brings you to a superseded part number 003 545 24 05. That is the same part number for the US cars. However, There appears to be a difference in the relays.

The 002 545 51 05 appears to be for cars with manual trannys. The superseded number is used on auto cars and the relay has a kickdown switch in it. I'm not sure what that means electronic wise, but must be making a difference because I've tried the OEM relay from my other (US, auto) 300CE and a brand new Kaehler aftermarket relay from US cars and it won't run with those. When the 002 545 5105 was current, there were two different fuel pump relays in use with W124s with the M103:

- 002 545 51 05 6 Zyl. 6550 min KVS, and

- 002 545 52 05 6 Zyl. 6550/min KVS Kickdown

The current parts lineup does not appear to include two correspondingly different parts. German EBay has several of the 002 545 51 05 relays available used, but are expensive enough with shipping to make me not want to just blindly take those chances.

Anyway, just hoping somebody might have some knowledge or data on this issue or a suggestion as to whether the original one is rebuildable and by whom. Thanks.

I'm with you on this one- the '89 190e 2.6 5 spd needs a fp relay; the one in the car is 002 545 93 05 and my FLAPS supplied me with 003 545 24 05 (6 cyl, 6450 kvs+ kickdown)

Some internet searching indicated that the original P/N was 002 545 5105 superceded by 002 545 93 05 superceded by 003 545 23 05.

FLAPS says the last number comes up no where, and said when they spoke to their benz guy that the P/N on relay in the car didnt exist on US cars.

I have a call into Phil to see if he has or knows of a FPR for the manuals, as the auto trans cars had a different set of P/N#'s

I have re flowed the solder in the FP relay twice, and there is one joint that is fugly, which I suspect is because the internal points are funky. I'm tired of doing this and want a new relay to eliminate it as an issue as I continue to chase down the 'why does the car stall occasionally at a stop sign' issue

Edit: Just got off the phone with MB Dealer- even running vin number the only part that shows is 003 545 24 05, with no options, footnotes or commentary.

Yeah, I've tried the Classic Center, German suppliers, nobody has a different relay for the manuals. This might be a mistake in the EPC. There may be a different relay out there If so, nobody knows what it is, so it can't be found.

In case anyone has a similar problem, Beckman Technologies will rebuild the fuel pump relay. So I'm buying a used one from Germany and will send mine down to Beckman in Florida to be rebuilt. Rebuilding cost is ca. $50.