Originally Posted by kwmccauley

Finally discovered the root cause to a problem on my 1998 ML320 (190k miles). The ABS/ETS warning light is on. The trouble code is C1304 which indicates a fault in the left rear HOLD solenoid. The dealer wanted to replace the ABS Hydraulic Unit and Control module @ $2,200. This work was declined and the vehicle was driven home without ABS.

Upon further examination, the actual fault is the pink wire that goes to PIN #10 in the 15 pin connector attached to the ABS Hydraulic Pump/Control Module unit (A7/3). This pink wire is completely abraded to the point that there is no copper conductor remaining. According to the wiring diagram, PIN#10 pink wire does indeed feed the left rear hold solenoid so this checks out with code C1304. Three questions for now related to the wiring repair:

1. What is the recommended splicing procedure, e.g. twist ends & solder then wrap, butt connector, insulation displacement connector, etc. ?
ANSWER: Snipped out about 1/2" of the damaged wire where the copper conductor was gone. Slipped about 3" of 1/8" diameter heat shrink tubing (the type with sealant) over one of the wire ends. Stripped ~ 1/2" of insulation from each of the two wire ends. Pushed the two ends together and made certain of good contact amongst the now interleaved strands. Soldered the wire strands with rosin core solder. When cool, slipped the heat shrink tubing over the repair and heated to shrink the tubing and seal the repair to make it waterproof. Wrapped the wire harness with new friction tape.

2. I may have done some damage to the 15 pin connector….not certain until I reassemble. What tool is used to remove the metallic terminals from the 15 pin connector block?
ANSWER: The original 15 pin connector block was damaged somewhat. A new one was available with MB part number 032-545-18-28 at a price of $14.40. This was FAR superior to buying a new wiring harness which was $600+. The only trick was removing the connector pins from the original block. If you do not have the correct AMP or Molex pin removal tool, one can be made from 3/16" OD aluminum, copper or brass tubing available at most hobby shops. The OD requires some filing (or lathe work if one prefers) to slightly reduce the OD. The ID fits over the connector pins and the OD must fit snugly in the connector block barrel. When the tube is pushed into the connector block, the locking tabs on the connector pins release and the pins can be removed through the rear of the connector. Sounds more complicated than it is. Just take your time and make sure you snap the connector pins into the correct location on the new connector.
2.1 Are replacement connector blocks available or does MBUSA sell a pigtailed replacement and all 15 wires must be spliced?

Thank you,
Ken