Does anyone know how to get the wiring harness computer connector apart? - PeachParts Mercedes-Benz Forum

GDC · #1 02-16-2008, 05:45 PM

I had been having an intermitent misfire on cyls 5 and 2. the codes kept telling me that there was a problem with the coil pack for those cylinders. I finally found that I have an intermittent short inside the computer connector. I proved it by unplugging the connector and found that pusing or pulling on the wire bundle at the base, I can make it go from 0 to infinite resistance.

Last summer, I rebuilt the wiring harness, but I spliced into the original wiring just before the computer connector because the insulation was pristine and it still is. But now there is a short. I can't seem to get the connector apart easily and I am afraid to force it. Any ideas?

Thanks
Greg

Carson357 · #2 02-16-2008, 05:52 PM

what year, model etc...

BMG · #3 02-16-2008, 06:12 PM

Yes and its a tough job

At the cylindrical base of the connector housing (black plastic) there is a hole in which the facory injected hot plastic to seal the wires into the housing. This effectively locked the inner white plastic piece agaist the outer blact housing.

I completely rebuilt my harness and this connector was a bear to pull apart. I was unable to salvage the wires doing it. I plan on a junkyard dive to acquire at least two 11 X 4 (44) pin connectors to basically canabalize to rebuild one good one replacing my existing piece.

You can cut a window into the black housing and perhaps get limited access to the wire from above. Unfortunately its VERY busy inside that housing.

One alternative is to determine which pin that wire is and with a needle nose plier see if you can pull it outward to get a little more life out of it.

Hope that helps.

GDC · #4 02-16-2008, 06:50 PM

Quote:

Originally Posted by Carson357

what year, model etc...

Carson357

Sorry, I thought I had it listed in my profile, but it doesn't show up. The car in question is my 1993 300E 3.2L M104

BMG

Was the cylindrical base of yours filled with some kind if white putty as well, or is this an indication that it has been apart before?

Greg

BMG · #5 02-16-2008, 08:50 PM

Aye - I forgot about that stuff - Sorta like silly putty. I used some of that to pack some of the connections at broken conectors.

The injected stuff is a yellowish tough plastic stuff - took forever to peel it off the few shielded wires I did not destroy.

After thinking about it, I recall the way to seperate the two pieces.

THere is a rubber boot on the female end inside the black housing. Remove that. You can then pull the white plastic insert downwards but only as far as the slack in the wires. Ergo the problem I noted earlier - Very little slack if any.

One option is to split the entire black house along its molding line with an exacto knife. If successful, you would have that part in two halves, the wires (fuesed by plastic and putty) and white connector. To reassemble, you would have to glue the housing back along that line. If you fail, time to hit the junkyard. My suggestion if your going to live with a DIY harness, its time to junkyard dive for several connectors. I am pretty sure they are the same for the 280-320 series.

By the way - did you rebuild your ETA harness as well?

GDC · #6 02-17-2008, 08:42 AM

BMG

Thanks for the additional info. I did rebuild the TA harness and all was well for a few months until one of the TA pots died. I replaced the TA at Christmas with a rebuilt one and it seems to be working fine. I'm hoping that the short didn't fry the ECU. As I looked at the problem further, I noticed melted insulation on the primary side connector to the coil pack for cyls 2&5 although the connector itself is not shorted. This is only on this one coil. The other two are perfect. I am having a hard time figuring out how a short at the ecu could result in high heat at the coil pack.

Greg

GDC · #7 02-18-2008, 05:25 PM

I called the dealer this afternoon. The parts lady said the part number for the connector is in the system, but none are in the US as they are special order from Germany. She said she would call me tomorrow and let me know price and availability.

BMG

Are the ECU's identical as well? Would one from a 280 work in a 300 assuming tthy were both M104's?

Greg

GDC · #8 02-19-2008, 07:08 AM

BMG

When you took yours apart, were the wires soldered or crimped into the connector?

Greg

GDC · #9 02-19-2008, 01:52 PM

The connector PN is 000 545 53 81 and the cost is $18.93. They come form Germany and the shipping is 5-7 days. Needless to say, I placed an order.

Greg

BMG · #10 02-20-2008, 09:34 PM

Greetings - I am traveling this week so not looking at the forums as often.

The wire lead end connectors are identical to those used in the plugs for the injectors. They have a mechanical crimp point. I would suggest that after crimping, you solder them to insure a permanent connection.

You fasten them to the lead first then push them into the connector. The tabs on it will lock them into place and are pretty much permanent.

Thanks for the part number. Looks like I will need to order one of those as well rather than diving for em.

BMG · #11 02-20-2008, 09:35 PM

Regarding the ECU's I have to defer to others here in the forum. I am new to Mercedes DIY work.

GDC · #12 03-03-2008, 06:37 PM

Turns out that the part I got was not the whole connector. It is the cover. The white pin body is not sold separately form the harness.

BMG · #13 03-06-2008, 09:51 PM

Only the cover?

That sucks. I reckon you could use your existing base by carefully extracting each pin. THis requires getting a slender pin in from the back to unhook the locking part of the crimp connector.

I was planning on getting a couple of these from the junkyard and simply cutting the base apart to get the connectors, then yanking the pins out a a second base. The reusing the good parts.

Looks like that junkyard trip is in order still. I saw several 11X4 pin connectors on several model years.

Good luck.