Anyone that owns a Renix era Cherokee knows or soon learns that proper grounding and clean electrical connects is absolutely vital to having a proper running engine. Along with poor grounding, high resistance in certain circuits that go to the ECM can cause the engine to run like crap or not run at all. One notorious connector that is flooded with intermittent high resistance problems is the C101 connector. The C101 connector is only on ’87 and ’88 years Cherokee’s and Comanche’s. The connector is jam packed with this gum like insulation crap. I’ll call it “TAR” for the sake of this article. I got this idea from Cruiser54’s – Tip 27: C101 Elimination.
As you can see in the picture, the tar is all over the inside of the connector. This tar causes intermittent high resistance on every wire in this connector that leads to the ECM. There are two option you have to remedy this problem.
Option 1: Use brake cleaner or electrical cleaner and a pick or toothbrush to clean the connector.
Now like I said earlier. This stuff is like tar. It’s gummy and a pain in the ass to clean. So cleaning the connector will take some time. Remember, you have to clean BOTH sides of the connector. For more instructions on this option, see Cruiser54’s – Tip 2: Renix C101 Connector Refreshing.
Option 2: Cut the wires on the back of each connector and solder the wires together and eliminate the crappy connector all together.
I chose option 2. I wanted all possibly of electrical failure, do to poor connections, to be eliminated.
To start the process, I disconnected both terminals from the battery. This connector has wires going directly to the ECM and I was going to be probing the connectors with a pick or small screwdriver. So to save myself from destroying the ECM or anything else, I just disconnected the battery.
Once the two halves were disconnected, I had to remove the rear connector covers to gain access individual wires. There was also a crap ton of that tar on the back of the connector. I took my pick and started clearing out the tar so I could see exactly where each wire was going.
Now that the wires can be clearly traced, it was time to get the soldering pen heated up and start cutting one wire at a time. I pulled back the split loom from each side to give better access to the wires that go to the connector. I put the two halves back together and started on the top left row of each side. I went one wire at a time to ensure I didn’t cross any wires. After cutting the first set of wires, I slipped a piece of heat shrink over one end and twisted the wires together in a “Y” shape configuration. (As space permitted.)
Once twisted, I coated the splice in Rosin Flux and tinned my iron. I placed my iron under the splice and heated the wires until my solder would flow on the top of the splice and coated the entire splice.
I let the splice cool for a few seconds then released the wire from the Handy Hands and gave the splice a good tug to ensure a good, strong splice. Once the splice cooled completely, I slid the heat shrink over the splice and completed the seal on the wire.
I continued this process, one wire at a time, until the entire C101 Connector was removed.
It started and ran perfect. I can’t say I noticed any real performance difference with regard to idle or drivability. But I did notice my instrument cluster gauges were reading a little more accurate. I compared them with my scanner and they appeared to be pretty dead on. Again, I can’t say this mod caused this but I’m glad I did it for preventative maintenance purposes. Anyone considering doing this mod should brush up on their soldering skills. Just remember to go one wire at a time and triple check before you cut a wire.