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landyacht318's avatar
landyacht318
Explorer
Nov 21, 2014

Engine Computer Connector

My ECM has 2 connectors, a 14 way connector and a 60 way connector.

The 14 way connector was compromised by techs prior to, or early in my ownership, probing the wire insulation.

Eventually wires broke entirely and my 'temporary', get me home fix( 11 years ago) was to drill through the connector insert bare stranded wire through the socket connector so that it was sandwiched between pin on the circuit board and the socket on the connector, and reseat connector.

This temporary fix turned a bit permanent, and some other wires suffered the same fate and treatment over the years. Rtv'ing the probed wires had only slowed down the process. The upside was that everytime things went wrong with the engine I knew it was this dang connector acting up again.

The pressure required to reseat the connector with this extra copper in the pin/socket apparently has broken the solder joints on the potted circuit board. Right now I have to wiggle tweak push and pull to get everything working normally, then immobilize the connector in order to drive.

Today I drove to the junk yard and scored 2 connectors from 89 mopars in pretty good condition, but I believe 2 or more of the wires is a gauge or 2 thinner than what is on My Vehicle. Not sure yet, but the wire color coding is almost exactly the same.

Would be nice to just splice in a new connector without worrying about the possibly thinner gauge

The tail end of the connector is enclosed over the wire insulation.

Read: it is not going to be easy to get fatter wire attached directly to socket inside connector.

One of the fatter wires is for the field control of the alternator.

While similar to molex connectors they are not the same. The pins on the circuit board are not tapered. Inside the socket there is a little arm which puts pressure on the pin/socket.

I've a reman'd engine computer in the mail.

I'd love to never deal with this connection again. However it is in a bad area and prone to moisture intrusion and also bakes since it sits about 10 inches over the engine.

I'd love to just rtv over the dang thing, but that seems a bit permanent and drastic.

The locking mechanism on the connector is also a stupid design and does not really hold it tight or even moisture tight unless huge amounts of dielectric grease are gobbed on.

But I d rather not have grease inside the pin and sockets, but just outside this zone.

Splicing the new connector in is going to be a bit tight. Sure be easier to use uninsulated crimps and quality heat shrink rather than soldering.

Any tips and tricks I am unaware of to make this a permanent solution to a decade long issue?

Also I am looking to have my old ECM rebuilt to have as a back up. Anybody have any recommendations on companies who do such things? Besides Cardone?

Would be great if I could get them to add an adjustable trim pot for the voltage regulator ;)
  • While this connector appears to be Molex standard sizes for pins and sockets and spacing, It is not.

    Perhaps the .092 sockets would fit over the pins and make an OK connection but there is no way to get them to seat within the plastic connector, and the spacing between sockets is different.
  • make your own

    http://www.ebay.com/itm/MOLEX-CONNECTOR-MINI-KIT-093-40-CONNECTORS-160-CRIMP-PINS-PARTS-BOX-200-pcs-/181594696073?pt=LH_DefaultDomain_0&hash=item2a47e32989&vxp=mtr
  • The issue is resolved.

    I'd bought a can of CRC electronics cleaner locally, and in combination with a sewing needle, was able to clean All the old dielectric grease from the sockets of the newly acquired junkyard connectors. I really got them super clean inside and out, along with the wire pigtails and was able to inspect them closely.

    There are 2 spring arms inside each socket which grasp the Pins tightly. I was able to rebend these inward to increase pressure, and on some of them, this clear thin material flaked off these spring pressure arms of the junkyard connectors.

    Perhaps it was hardened dielectric grease, or something else, but I spent more time making sure that each socket was devoid of this mystery clear flakey substance.

    The wire insulation on the pigtails was sandwiched within the plastic connector end, and some small splits in the insulation adjacent to plastic revealed shiny copper under a strong light on a few of the wires. I used liquid electrical tape over the base of the connector upto 3/4 inch up the wires. Many layers applied hours apart over 18 hours to both Seal the insulation and act as stress relief.

    There were no thinner wires in junkyard connector than stock connector. Only one wire was of different color than stock, and this wire was a gauge or two thicker than Stock. So no concerns in this regard.

    I soldered the new connector in, one wire at a time, and used 2 layers of unequal length heat shrink, after wiping off flux residue from wires and solder with 91% rubbing alcohol.

    When I was done, the UPS truck had yet to arrive with my reman'd ECM, and for grins I plugged the new connector into my Existing ECM. I expected to be able to put pressure on either side of connector base and stall engine, but it was not to be. I wiggled connector, push/pull, side to side, up and down, all around, and engine never hiccupped.

    I turned it off, did key dance to check computer codes, and the 8 year long existing code 53( internal PCM fault detected) was gone.

    So all along it was the connector. I am a fool for not attending to this long ago.

    When the UPS truck with my Reman'd ECM arrived, I plugged that in, and it started the engine, and it ran fine, but the Check engine light Illuminated, and the key dance revealed a code 27, for a Fuel injector. So it is going back as a defective product.

    I rebent the arms on the sockets. Blasted connector and socket again with a little more CRC QED cleaner and applied undiluted Stabilant 22 contact enhancer, that I already had, to both pins and barrels.

    I would have loved to have had the Caig products on hand, but money's running low, and they are not cheap, and the Stabilant 22 is supposed to be a dang good product too, and I already had it, and more importantly, was able to find it.

    I reseated the connector, and put a 4 inch narrow extension tip on my new tube of Dielectric grease, and filled any air voids between connector and connector receptacle with dielectric grease to seal out air and moisture, but there is no dielectric grease between the electrical contacts, only around the exterior of the connector.

    The wires for this connector are now a few inches longer than previous, and I have used some zip ties to secure them out of the way with no stress on the connector, but still have a few Ideas to implement to keep any gravity, or airflow assisted rain water from reaching wires or connector.

    So hopefully the ECM seller through Amazon does not give me a hassle returning the defective ECM.

    I still want to send my original ECM somewhere to be rebuilt to have as a backup. My currently functional one is a remanufactured one. I really do not want to have to disconnect the connectors to test a backup but it will be required to test, and perhaps at that time I can use the Caig products.

    But for now I don't have to worry about random stalling at speed.
  • Thanks Mex.

    Just re checked my factory service manual. It says the 12v feed from the alternator is to be 14 awg, 2 ground wires are to be 16 awg and other 11 are 18 awg.

    The junkyard connectors appear to meet these gauges. I am not exactly sure which wires I have replaced on my current quasi functioning connector. Often I had to add some wire to reach through the socket and used what was on hand which was likely thicker. The splices disappear into the loom and the back of the connector was RTV'd and my memory is not infallible.

    This is a very old picture of the connector in question likely from the first time i ever removed it: This was well before I drilled through the socket and inserted bare wire through and hooked it over the tip of the socket. Notice the socket tips are already out of round.






    So it appears the previous owner or some tech had been inside this connector before and tried to tighten up the sockets.

    Anyway both my junkyard connector aquisitions are in much better condition than this. I still need to get all the old grease out of them. One of them the grease is dark, like they used axle grease. Both took a lot of cleaning just so see that the wire insulation has never been probed, which is why I grabbed 2 of them.

    The pics also show the locking mechanism. A slot top and bottom of the connector on the computer, and a corresponding ridge on the wired connector itself.

    This is hardly a locking connector, and far from being air or moisture tight.

    My longest period of no issues from this connector was when I used some peel and stick roofing material over the connector bridging computer case and wires.

    I recently tried to do the same thing as part of a 'get me home immobilization' as this issue reflared half way through a 1750 mile roadtrip, but the pressure was not correct. If both TBI injectors were firing, then the alternator was not charging. Slight tweaks in pressure are required to get both TBI injectors to fire and charge the battery, and it always seemed to stall outright when going downhill and hitting a bump and often I'd first notice by the lack of power brakes as I think the 12v feed to the circuit board was tripped as no lights on the dash would come on. The only visual indicators are my aftermarket mechanical oil pressure gauge and voltmeters dropping.

    I have concerns that any conductivity enhancer will bridge the pins and sockets. I do already have some Stabilant 22a on hand. I used it on my road trip when i also cleaned the sockets with a diamond coated fine dremel bit and rebent them to ensure a tight connection, but this actually made the issue worse which made me suspect the pin's solder connection on the circuit board was compromised as reseating took even more force, and pulling on the connector afterward activated injectors and field control.

    I have concerns that the connection is hardly air or water tight, or even tight when seated.

    Looks like Caig has 2 dozen different products which overlap on their function.

    Standard molex connectors seem to have a 25 insertion cycle. This is not standard molex but there has to be some degradation every seating removal cycle.

    I kind of don't want to resplice connector until I have new ECM on hand and do both at once.

    But I fear stalling somewhere inconvenient in the mean time
  • MoPar had two alternator models for that year. A 40/90 and 50/120

    Even Though both the Bosch and Mistubishi variants (interchangeable) used EXACTLY the same rotor winding resistance in both the 40/90 and 50/120, in their infinite wisdom they decided to increase wire AWG by one number. Pretty fartsmellers those engineers. My toad has the 18 gauge wire and it works perfect.

    But MoPar had a grand fit of the stupids with mine, mounting it inches from the battery.

    I found the bottle of the preservative. The label sez...

    DeOxit D100 SHIELD

    For computer edge connections, antennas, USB connections, automotive ECU connections and sensors, there exists nothing and I mean zero competitors that do what these two products do. My friend Eduardo was stunned when his new out of the box laptop showed only three bars wireless strength on his new out of the box ALFA antenna was connected*. I used D100 cleaner and bar strength jumped to max, 5 bars. I added a drop of Shield, and since last May his computer remained at 5 bars. Wife Vanessa, brought me her new Tosiba laptop and the same thing happened.

    Same antenna, same location my dinosaur Compaq was getting 5 bars.

    Yes I am an advocate of CAIG. I like things that solve problems.
  • For those wires too small for the current load, could you splice some extra wire on and use an additional set of connectors?


    It was such a lovely day I thought it a pity to get up. --- W. Somerset Maugham
  • MoPar has lots of service bulletins that state the use of silicone dielectric grease on any ECU or sensor plugs or sockets will interfere with component communications.

    I just tried to bring up the CAIG.COM website for you but bad microwave tonight - you'll have to do it.

    CAIG sells two miracle products that are right up your alley

    DeOxit D100

    Preservative in a blue bottle (keep rooting around and you'll find it)

    The D100 is full strength oxidation remover, the blue stuff is designed to protect computer connections in salt air environments. The D100 does not protect and the blue stuff does not clean.

    Lockheed uses it on F18 Super Hornet aircraft, Boeing uses CAIG, Northrop, ATSF railroad, on and on. The products are unique, nothing else in the world works as good for cleaning bad contacts and then protecting them from severe environment oxidation and corrosion.

    The stuff is not cheap. I'm cheap and I wouldn't be caught dead without the two items - they are that good. They are focused on microprocessor contact oxidation removal then protection without disturbing tiny signal voltages.

    http://www.caig.com

    Hope this helps

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