88XJ Wiring Harness Upgrade Kit #83100066

[CJR]

Jeep came out with a wiring harness upgrade kit, #83100066, to improve 87-90 XJ connections to the ECM. I did a search for this wiring harness upgrade kit and came up with zip. Anyone know of a good source (new/old JEEP OEM stock) that may still have this kit?

Best regards,

CJR

 

[cruiser54]

Probably not available anymore. I have the TSB if you want it. It was a bear to install. We installed a boatload of them at the dealership over the years.

I now do my own bypass of the C101 connector and it works as well. Have you ever checked your CPS output?

 

[Matthew Currie]

At one time Renix crank position sensors could be bought with an upgrade kit - just the one piece that bypassed all the rest and went directly to the ECU. Oddly enough, this kit was cheaper than the plain CPS.

Some time between 1988 and 89 the whole harness changed, eliminating the bulkhead connector. If you're really in the mood to do some harness upgrading, it might be worthwhile to see if you can get the whole shebang from an 89 or 90. As I recall, it came in two parts, one for the fuel injection alone, and the other for all the rest of the engine management connections. It was a lot neater than the original type. As far as I know, there were no changes in the components, so it should be a direct swap if you're willing to take the trouble. As you're probably aware, the ECU is in a very inconvenient location, so doing anything at that end of the harness is a chore.

An alternative, done by at least a few people here, is simply to bypass the bulkhead connector. Snip and solder.

 

[cruiser54]

Snip and solder works well. I intend to do a write-up on it someday.
Basically you find the wiers and their colors at the CPS connector on the harness side, split the loom open, trace the wires to the C101. Find the same colored wires on the opposite side of the C101. Verify continuity with an ohmeter, snip the wires, bring them together and solder.

 

[Matthew Currie]

My only reservation about snip and solder on an older XJ is that the miserable quality wiring sometimes tarnishes enough inside the jacket to make soldering difficult. It's still possible, but can be tedious because you may need to spread out the strands and scrape or buff them shiny before solder will take well. It's worse near the ends, and I've had to do a good deal of prep on things like headlight socket replacements. It's still a good permanent repair if done carefully.

 

[jakbob]

c101 removal
http://naxja.org/forum/showthread.php?p=245423882#post245423882

 

[CJR]

Thanks everyone for helping me. It's appreciated! If this harness is no longer available, then running separate lines from the CPS to the ECU connector looks like the best option.

Best regards,

CJR

 

[O-Gauge Steamer]

My wiring .02...

When cutting into an elderly harness, move well away from the connector as the wire will, in fact, tarnish. Which is to say corrode. You can use a mild acid solution to clean the wire but then you will need to neutralize the wire prior to soldering it. If you get far enough back from a connector, you can find clean wire. Acid core solder has been known to work but I really can not advise using it. Left untreated, the residual acid from the core will promote corrosion.

How far is far enough? Good question. Next question? There are a ton of variables the primary one being the environment into which the Heep has been sitting. How many exposures to water. How old is it, Ad Nauseum.

Corrosion is everywhere. For instance, do not use a graphite pencil on aluminium as the graphite will start corrosion. Alcohol based inks or grease pencils are to be used. Everything has a downfall and Rust Never Sleeps...

 

[cruiser54]

Lots of good advise here. Have you ever cleaned your C101 connector?

Renix Jeep C101 Connector Refreshing
　
The C101 connector on 1987 and 1987 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and resistance increase over a period of almost 25 years.

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease to the connection and bolt it back together.

 

[CJR]

Cruiser 54,

My 101 connector is spotless. Year ago, when I first bought my 88XJ, my 101 connector was PACKED with gunk, dirt and grease. I soaked both ends of the connector in small cans of solvent for a couple of days. Then with picks, toothbrushes, spray solvent etc. I cleaned both ends. Then each connection was coated with DeOxit. Now, once a year, I disconnect the 101 connector, spray with solvent and recoat each connection with DeOxit. That seems to insure good corrosion-free connections in the 101 connector.

Though I've never seen a #83100066 harness, I would assume the wire gauge is larger. If it is a larger gauge wire, then a direct connection to the ECU would be worthwhile.

Best regards,

CJR

 

[cruiser54]

IIRC, the gauge of the wire is the same. It was just a kit to get as strong a signal to the ECU as possible. The kit had to be "bolt-on" and not require wiring harness mods or soldering. If your CPS generates .5 AC volts I believe it would get through your C101. Test the CPS output first.



Renix CPS Testing and Adjusting
　
　
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the 3.5 range on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.

 

[CJR]

Cruiser,

I like your VAC testing of the CPS rather than resistance. But, how fast the engine cranks ,during start-up, affects what mean VAC you measure from the CPS. Therefore, if I get a low VAC signal from the CPS, the CPS may be OK but the root cause may just be a low battery, bad electrical connections, or how far away that particular CPS is positioned from the flywheel teeth. So changing out the CPS may not cure a weak VAC signal, particularly in the case the new CPS is positioned further away from the flywheel teeth because of manufacturing tolerances.

It would seem to me, that a slotted CPS (for faster removal/install) and some precise way to minimize the spacing of the tip of the CPS to the flywheel teeth, without touching, would be nice. Then one could easily/accurately position the CPS as close as possible to the flywheel teeth to get the maximum VAC signal. What I'm saying here is; if the CPS tip spacing to flywheel teeth is spec'd at 1/16", may be the spacing needs to be precisely reduced to 1/32" to get a stronger signal.

Best regards,

CJR

 

[cruiser54]

I agree. So what is your VAC reading now?

 

[CJR]

Cruiser,

I haven't measured my CPS VAC recently. Early, this past summer, I had some CPS problems and replaced it. It's been running fine since. But I started this thread to see what the general consensus was for improving the CPS/wiring, etc. I've since discovered that the quality of the CPS and its wiring can be improved as well as slotting the CPS bracket to speed up removal/replacement.

Best regards,

CJR

 

[cruiser54]

You might check the VAC at the CPS plug and then again at the other side of the C101.

It would be interesting to see what readings you get. And then you'll know where the wires are to do the following:

Me, I just bypass the C101 with the CPS wiring. Solder only. The factory didn't bypass the C101 for nothing......

 

[CJR]

Cruiser,

If I understand what you're saying; you simply pull the CPS wires, from both sides of the C101 connector, and solder them together to bypass the C101 connector? That would be equivalent to installing the upgraded CPS wiring harness.

I don't understand your statement; "And then you'll know where the wires are to do the following:"

Best regards,

CJR

 

[cruiser54]

You understand correctly about bypassing the C101. Technically,it' might not be quite as good as the factory bypass kit, but it's always worked for me.

"And then you'll know where the wires are to do the following" meant that if you tested the CPS ACV at the plug and then after the C101 you would already have located the wires necessary to do your own bypass.

I have thh TSB for the factory bypass if you'd like to see it, not that it makes a difference, but it's copyrighted material so I can't post it here.

 

[CJR]

Cruiser,

Thanks for the clarification. It's appreciated! Likewise, thanks for the TSB offer. I already have that 6 page TSB.

Best regards,

CJR

 

[cruiser54]

After reading the TSB, the method we're discussing seems downright easy!!

 

[Ecomike]

My only reservation about snip and solder on an older XJ is that the miserable quality wiring sometimes tarnishes enough inside the jacket to make soldering difficult. It's still possible, but can be tedious because you may need to spread out the strands and scrape or buff them shiny before solder will take well. It's worse near the ends, and I've had to do a good deal of prep on things like headlight socket replacements. It's still a good permanent repair if done carefully.

Household ammonia works wonders de-oxidizing and cleaning copper wires. Then use 90% IPA (Isopropyl alcohol, from walgreens), or perchlorethylene brake cleaner (aerosol), to wash off the ammonia and dry the wire ends. Then use rosin flux silver solder.

That said, I have found solder is not always the best approach, as moving wire connections tend to fatigue with age and break right at solder joints over time if they flex at the solder joint. If you can keep the solder joint from flexing, it tends to be OK.