W124 E420 Engine Wiring Harnesses
 

Greetings,

I have occasional runability problems that were traced to deteriorating wiring around the temp sensor. I gather there are two harnesses, a main harness part number 1244409406, around $1400, and a fuel injection harness part number 1244401906, around $600.

The FI harness, then, is the one to replace if one has runability issues. The other main harness, is that for lights, wipers, horn, etc.?

Thanks!

99% of the time the problem comes from the Fuel injection harness, which has the temp sensor in it (as well as other few sensors).

I did not buy a new one, but rebuilt the old one.

I've never heard of a 94 06 / body mounted harness failing. The 19 06 / engine harness will have to put be replaced at some point if it has not been replaced already. You should be able to find it for around $500 or it's not that hard to build a new one.