Glow Plug

[rbarrett]

Just found a bunch of wires under the intake manifold of my 1995 E-300D that were cracked and shorted and really a mess. They need replacing. The wires go to the glow plugs and to three other two prong plugs that I cannot find mention of in the repair manuals. Not sure about them except that they need to be replaced. I took the plastic wire run cover off and all the wires in there are cracked and brittle.. I have not disturbed them as I am not sure that I can buy a harness. Has anybody out there had a problem in this area? Does Mercedes carry a harness for one this old..? Just trying to get a jump on something that might cause me to sell the old girl... no other problems at this time... everything seemed to be working fine.:-?

 

[Number_Cruncher]

>>Has anybody out there had a problem in this area?

Yes

>>Does Mercedes carry a harness for one this old..?

Yes - about £300, and it takes a quiet hour or two to change over, but it's not difficult - as you'll have found, there are lots of little jobs to be done while the manifold is off.

 

[Cole@MBS]

new engine harness required - the old one can be repaired but will never be as good. MB do stock these at Milton Keynes due to the massive failure of these engine looms!

 

[rbarrett]

Thanks for the quick reply. Is the replacement difficult to access under the dash... I saw that the harness went under the dash and it was getting pretty cold outside so I haven't crawled up under there yet..... :-?

 

[Number_Cruncher]

>>Is the replacement difficult to access under the dash

No, it doesn't go under the dash - it goes via the false panel in the bulkhead to the well area by the brake servo and master cylinder, where there's a multi-plug. You do the entire job in the engine bay.

 

[rbarrett]

Thanks.... you have made my day.... This car has been the best.. I am a Merchant Marine and I am gone a lot of the time. This car has been absolutely faithful for over 12 years!! But.... she's getting old...

 

[Number_Cruncher]

Difficulties;

There is no alignment tag on the 4 wire temperature sensor, so, check and sketch / note down wiring colours/layout before unpluging.

There's an extra plug on the new wiring harness near the injector pump - again, if you change only one plug at a time, it will be obvious which is not needed, and you can just tape it up out of the way.

Other than those 2 points, it's a doddle.

 

[rbarrett]

Well, I got out there this morning before I read your post, Number_Cruncher.. and I pulled the whole works out after I ordered one...(US)$440.00. I'll have to figure that one out tomorrow... It is hard to believe that they would have a 4 post connector without an alignment post:-x!! The previous wiring harness had a pair of wires just terminated (spelled "cut-off"):???:. I guess that would be the extra pair that you mentioned. Thanks again... Ps..while I was in there, I found the leak in my A/C system that had been eluding me.. the txv, under the diaphram.