Connector and Relay/Receptacle Refreshing


10-pin connector

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together.

There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.

ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.Ballast Resistor

Revised 1-31-2016

42 thoughts on “Connector and Relay/Receptacle Refreshing”

  1. Hey Cruiser, my 87 Jeep Wagoneer 4.0 does NOT have these fuel resistors, I purchased it this way and I did notice them hanging from the wire loom but didn’t know what they were at the time long story short the idiot that installed my alarm decided to clip and remove them for what reason ? I don’t know all I know is my jeep has ran ok aside from having a bit of rich fuel mixture and Nox on the dyno is pretty high. Should I re install them or just leave alone?

    1. Fuel resistors? Do you mean fuel pump ballast resistor? If so, that can be bypassed and the pump MAY be a bit noisier.

      How many of the first 5 Tips have you completed so far?

  2. Mr Cruiser, have you found a fix for the Ignition Switch weak or overloaded terminal at the #10 gauge Brown wire connector?
    The AZ Duralast switches dont last long, a few years maybe.
    My last one was a Delco Remy jy find off a GM tilt column.
    It is going bad now, so I was hoping for a long term fix.
    Any pointers are much appreciated. Colin

    1. I haven’t. It was a known problem on GM cars also.

      Perhaps do whatever you can to make that particular connector at the brown wire tighter? Tweak it a bit and use some Noalox on the pins sparingly. It’s a conductive grease that also seals out oxygen.

  3. What do you think, Cruiser, about including Greg Smith’s relay-modification/upgrade/improvement in the passenger door, to improve power locks performance?
    Also in that Greg Smith thread on NAXJA website, there is a mention of wiring modification to help with the power windows.
    Seems like the power lock solution is a major winner for many, and the power window solution might be.

        1. I was referring to the fix for power door locks mention in this thread. Something about the fix being in the passenger door.

  4. Sorry, what I meant was to include the mod/upgrade/improvement in your list of Mostly Renix Tips. It seems to be endemic to all the XJs from the Renix era and beyond.
    Tip #39, perhaps?! 🙂

  5. I took a look at my front light harness connector because my front turn signals do not work, the arrows in the dash only glow solid when the headlights are turned on. Upon taking the connectors apart several wires on the front light harness side were completed corroded and broke off of the pins. It appears the source side connector and its pins and wires are in good shape. Is there a source for a new harness, or at least the connector and pins? Or am I better off replacing with marine heat-shrink push together terminals, or should I go one step further and put weatherpack/ metripack connectors on the wires? I also have a harness to put the headlights on relays in the mail.

    Thanks for the help!

      1. It’s kinda tucked between the back side of the driver side headlight and front of the air cleaner.
        That said, I would inspect the outside lamp that’s not blinking first. The sockets are notorious for getting crudded up.

  6. I eliminated my ballast resistor. When I found out it was to lower voltage to the noisy fuel pump at idle for NVH I took it out. The new pumps are quiet so there is no need for it. I decided to use the wires for a kill switch. Your tips are awesome and greatly appreciated, I love my 90 Pioneer. I have had it since 2009 and converted it to 4wd. I fixed a lot of things before they broke because of great guys like yourself posting all this great info. Thank you sir…

  7. I noticed that there is a large electrical connector pluged into the firewall on the driver side next to the brake booster, goes to the fuse box.

    Any idea as to how to get it unpluged for cleaning?

    Thanks in advance

      1. Well, I removed the large plug from the firewall that connects to the fuse box. Not too bad removing it. It may be a PITA trying to reconnect it though.

        Inside is a lot of hard black sticky substance covering the contacts. I assume it is some kind of dialectric greese that has gotten hard over the years.

        In your opinion do you think it maybe hindering the connection a bit?

        If so do you think it should be cleaned out and replaced with fresh dialectric greese, if that is what it is?

        Thanks Cruiser. What would we renix owners do without you!

  8. Clean it out the same way as you would the C101 connector in my Tips.
    That gunk was just like that when new. Clean it out real well. No dielectric on it. The connector you are dealing with is the C100 BTW.

  9. Cruiser, while fiddling with the headlight connector, C102, in my 87 MJ, one of the wires broke off – Red wire, pin 6. It provides pwr to the fog lamps (factory option). My question: what type/brand of connectors were used/installed on the Jeep (weatherpack, etc) and the connector size?


    1. I don’t think that connector was a weatherpack. They have the little spongy rubber center pieces.
      Most all the connectors can be found in the junkyard or are sourced from GM.

  10. Hey sir, my (new) fuel pump is pretty darn loud on my 87. I do not have a ballast resistor. Should I follow the FSM on adding one? I already refreshed my ground and have 12+ volts at the pump harness. It sounds like it is max duty all the time.

    1. The noise was never really an issue except to the most discriminating owners….
      Did you get an Airtex or Carter pump?
      Get the little rubber snubber on the bottom on reinstallation?

  11. New reader here, Adding some info to this thread. I needed to replace my 1988 fuel tank and pump. the replacement tank did not have the small circular metal donut that the snubber engages. so i turned the snubber upside down on the fuel return line. It’s shaped like a cone and when it’s upside down the large dia acts like a foot on the tank floor helping to support the pump and reducing noise. i also drilled 4 radial holes in it to allow return fuel to pass through. I have had my XJ since new, been sitting for 20 years in the garage! Getting it going again. love all the tips here.

  12. Hey cruiser54 I’m having an intermittent issues with a misfire in cylinder 6 with my 89 cherokee its somthing going on with the injector wire it keeps working then not working I know the injectors are good if you pull the plug off #5 and put it on 6 it will work ive gone through your tips 1-5 I’m starting to think it the computer again

  13. Any suggestions or thoughts on loading up the freshly cleaned electrical connectors with dialectic grease or something else to hopefully prevent future corrosion?

  14. Hello Cruiser. Awesome site you have supplied us with. Thank you for the wealth of knowledge and experience. I am completing step 3 on My 88 MJ and was wondering if you suggest applying some Dielectric grease after cleaning out the connectors? Do you leave them clean and bare? Thank you very much.

  15. Great site! I bought a 85 Cherokee pioneer new in 85. Loved that thing except the 2.8 liter v-6.. gave it to my Son in 2016 when he turned 16. It had 245k on it when he traded it for an 87 Comanche. Ironically
    39 years to the day..Dec. 2nd I saw a 4dr
    XJ Laredo sitting in a field. I asked the home owner about it and replied he was trying to get rid of it. Clutch is out of it(5spd). After removing layers of moss&
    Debris, it’s coming back to life!
    It’s in my driveway and I’m reviving it!
    If the fuses are good.. any idea why radio/ power antenna aren’t working?
    Cigarette lighter, and clock illumination?

  16. I have found that the fuse was blown on the back of the radios head unit.
    I replaced it and it briefly came back to life
    I then installed new kicker rear speakers but the sound was faint at best. I thought it might of been because of the power
    Antenna , but it is in up position it just doesn’t power up & down. I had fm stations display. So I decided to put in a cassette still no sound but it did FF /rewind. Then switched to fm again now no display. I will just put in an aftermarket,just wanted to spend money on other things. Clocks bulb was just out and the lighter socket had power it was just the lighter itself. Rear wiper had
    Previous water intrusion, I took the motor apart and removed rust on the magneto
    And I’m in business.i live in Oregon, need that rear wiper. Lots of things solved but here is my new challenge.
    Overhead console compass/outside temp.
    I found the sensor. Now what? Is there a fuse somewhere in the panel for it?
    I have power for the 4 courtesy lights in the overhead,but don’t know how to test the rest of the connectors to see if there is power to the circuit board itself, or is it just the board , and how can i test it
    Or am I being ridiculous and concentrate on more important things like the clutch?
    Its just that I’m trying to get everything else good while waiting to save a little extra cash!

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