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Discussion Starter #1
Hi!

My vaccuum pump suddenly stopped working 2 days ago without any previous warning...
I removed it and opened it and found out that the motor was completely dead(burned out as it seemed to me)!

Anyway I already had the same problem 2 years ago and replaced the motor(only).
Now, beside the fact that the motor blew up in the past, I was sure their was an internal leak somewhere because it was always running. Anytime you activate it it would run for about 15 to 20 seconds before shutting down.
Even though I was leaning toward the possibility that the leak was coming from one door or another; now I'm sure it is coming from this dead pump! Indeed I have a spare pump and as soon as I installed it it ran beautifully and instantly shut down just after accomplishing its operation.

The only issue now is that this replacement pump doesn't disable the anti-theft system and therefore doesn't allow me to start the engine!

My original (dead) pump pn# 1298000948

The replacement pump pn#
1298000648

Is there a way to make it work?
I don't want to swapp the motor only; as I did the last time because I'm sure the old pump has this internal leak... is it possible at the contrary to swapp the electronic board??
Please help...
 

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Discussion Starter #2
Well guys back again!

As I didn't get any advice/comment on this forum and as I drive the SL daily for a long time, I decided to go ahead and swap the electronic boards from both pumps+the vaccuum system on top of the board. Means I kept the motor+the vaccuum system from the donor pump (pn 1298000648) and I replaced the electronic board which looks somehow different from the original pump (pn 1298000948).
To do so, I desoldered the different wires that were connecting the board to the motor &the vaccuum system and resoldered my old original board (which I cleaned thoroughly with electrical contact cleaner hoping that it hasn't been damaged by the heat generated by the burned out motor). Then I carefully positionned the motor and put back everything in the correct way inside the housing and finally tightened the housing using the original couple of screws on the bottom of the housing.
Finally, I installed it back in the trunk and tried locking/unlocking the doors; which was succesful(quick and instant with no delay). And praying that the board swap did the trick; I tried firing the engine and it did it too!

All this lead me to the conclusion that yes, the vaccuum leak that was making my old pump run for almost 20 seconds each time I used to lock/unlock the doors was indeed coming from the pump itself and not from the doors/trunk locks actuators. Also, yes you can swap either the motor alone; the electronic board; or both in the same time. Even though there was an obvious difference in the board components, the main plug is the same, the wires the same number; sequence; color. The proof is that it worked for me...

So if you guys have a spare working pump and need to replace yours because of an internal leak or a defective motor, and if you have the basic knowledge of soldering/dismanteling electronic components, my advice is to try to replace what you think is defective and put back the repaired pump in your car and try to see if it does the trick rather than go and buy another new/used pump!
They are basically the same, especially te old ones from 90/95. I saw many of them and they are almost same.

Hope this helps.

Regards!
 
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