main wiring harness grommet on firewall ?

[merrill]

So,  yesterday I painted the engine bay on my 230 sl, really not much fun, but what a difference a fresh coat of paint makes.

My question is,  i have the firewall grommet set from K&K MFG.  and i was not intending on replacing the main wiring harness grommet as the harness comes thru the firewall.

after looking at how deteriorated mine is, and how nice a new one looks, are there any tricks to replacing this sucker?

It has a large hole to accomidate the harness, i was wondering if the hole is also large enough to accomidate the various plugs on the harness or will I have to remove the plugs??

If so, I may pass.

thanks
matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[George Des]

Matt--I re-did my wiring harness as part of a major restoration on my 230sl and faced this same problem. I think you will find it all but impossible to thread the harness through the grommet w/o removing the plugs. In my case, I split the grommet and have it tied together with a black plastic tie wrap for now. I may eventully use the same type glue recommended for split axle boots to close the seam, but for now it is fine. Ray Schlict told me he went through the tedious task of actually doing the threading to keep the grommet intact. You may want to find out from him how long it took and any tips he can offer. I think he frequents this board.

George Des

[merrill]

George,
I have an extea one, so, If I am successful installing one I will give you the extra one.

I will let you know

matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[merrill]

so, just finished the task,  It took me about 6 hours.

here are some tips.  

1.if one is to do this get new grommets for all the locations on the harness.  might as well get it over with in one job.

2. the main harness is made up of 2 legs. I did the drivers side leg that runs up to the drivers side headlight and then over to the passenger side.

3. have a pad of paper ready and marker and a small flat head screw driver with a big handle. some of those small screws are really on there.

4. have a wire or small rope available, I found it helpful to pull the wires thru the new grommet rather than try to push.

5.  once a plug is removed,  use tape to hold the ends together and I found may even hold the wires in their correct position when re assembling.

6. when pulling the grommet along use water to lubricate the harness thru the grommet.

7.  do not remove the old grommet until the new one is almost in place. nothing worse to remove the old one and have the new one break during installation.

good luck
matt

Matt
Austin Tx
66 230 sl - "white"
78 300 D - Blue
98 C230

[RCS Coupe]

Good tips from Matt. Some of my experiences:
For my paint I had completely removed all of the wiring harnesses, front-to-rear. I cleaned every linear centimeter of wire and checked the continuity of all circuits. Replacing some of the plastic and rubber sheathing (source: Rhode Island Wiring) as well as all rubber grommets as the harness went back into the body. The wiring is a tight fit through the grommets, as it should be, since they are there to exclude water and dirt. This means it requires the removal of all plugs before shoving the wires through using some sort of lubricant. Water works, I used a light coating of silicon stop cock grease (Dow-Corning DC-11) to help slide them through.

To reinsert the main harness grommet back into its firewall hole is not particularly easy. Access to both sides of the firewall at the same time works best to help lip the rubber through the flange. I sat in the engine room with one hand through the opening for the steering column while working the rubber lip of the grommet from teh engine side with a stiff nylon blade.

The whole operation takes hours. Don't know if it was all that worth it since it takes a sharp eye to see that the grommet is intact and not put on split the way George Des did it. Also, you will note that some of the smaller firewall grommets come from M-B already split!



Ray
(268)Green 250 Coupe

[George Des]

On my harness, I completely removed all the vinyl covering and repaired any spliced or weak looking areas with new wire. All these repairs were made with the color coded wire from RIW and were done properly with solder and shrink tubing over the splices. It would not have been out of the realm of possibility at the time to do a completely new harness using the original as a template. Had enough pins and sockets and the right color coded wire, but it definitely would have been time-consuming and my orignal one was basically okay. With the new vinyl covering, it looks great. Replacing the vinyl covering does require lots of planning to make sure the branches come put right. I elected to split the firewall grommet because I could see just what an effort it would be to get the wiring through with the grommet intact. I have the grommet turned split side down and pulled together with a black tie wrap. The hole in the firewall itself holds the grommet together at the point of entry and as I said, a little rubber boot adhesive would probaby vulcanize it together if at some point I need to do that.

George Des