Working on original bulkhead connector
I have narrowed down my non-operational ammeter to an intermittent connection problem on the leg of the ammeter circuit that goes to the starter. Everything else checks out OK, and when I put the "right" twist on the bulkhead connector, the ammeter starts working again. Release it, and it's back to non-functional. So I know I have to take the bulkhead connectors apart and clean the connections. However, my car has it's original wiring in it, which is 47 years old, and even I can see that it's a little dried up. I did a preliminary attempt to remove the connectors on the wiring harness from the firewall side of the bulkhead connector, and can see it's not as simple as unplugging a lamp. So before I get in there and do some potential damage, does anyone have any tips on how to do this with the least risk possible? Should I spray it with Armor-All or something similar to soften it up? How about using a heat gun to bring it up to 150-200 degrees to make it more pliable? (I have an infrared thermometer, so I could make sure I won't burn it up.) Any suggestions out there? I'd really hate to screw this up on a 73K mile car.
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Re: Working on original bulkhead connector
Be careful with the plastic ears that hold and release the connector to the firewall. At this point they are very brittle. Not sure you can do anything about that. Use WD40 for some penetration and lubrication. Take your time wiggle and pull. You should be OK taking your time. I would disconnect your battery before you start. Once apart Radio Shack has an electrical contact cleaner in a spray that will help. Be prepared to possibly find a lot of green corrosion. Each pin connector is very fragile as well. -
Re: Working on original bulkhead connector
Dennis,
Chances are that corrosion is your issue, but don't use a spray product or heat to try to repair. These are mechanical connections and use a unique mating pin. The "Twinlock" pins can be carefully removed with a small tool from the front, on each side of the pin.
Twinlock_Pin.jpg
It would be best to inspect each of your forward harness connectors and check each pin. The flat blade which mates to the opposite pin in the bulkhead connector can sometimes loose it's tension. If you find one that seems more flat than the others, you can carefully pry up the blade. To remove the pin, see below.
Twinlock_Pin_text.jpg
There was a thread which discussed this recently, HERE. Bill Clupper had some good info about the "Twinlock" connector which I researched. In that thread I found a website with info but unfortunately it's now unavailable.
There is a repair kit available with new panel and pins but you may be able to repair yours. E-802
e-802_71.jpg
RichComment
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Re: Working on original bulkhead connector
Terminal Supply should have all the contacts and connectors you will need. I think those are Molex or Amp terminals.Comment
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Re: Working on original bulkhead connector
No. sorry, exclusive Packard Electric design although clones may be available from other sources. depending on the circuit, some had a base material of Berylium-copper alloy for improved conductivity on the high current circuits.Bill Clupper #618Comment
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Re: Working on original bulkhead connector
Thanks for all the information. I did a search, and couldn't find what I wanted. I am more concerned about getting the connectors apart without damaging them the actual connectors themselves. With the type of problem I am experiencing, I hope a simple cleaning will be all that is required. I have a can of contact cleaner and plan to use flat toothpicks if any "manual intervention" is required. I did have a problem with corrosion on my headlight switch that was causing my dash lamps to not function and it cleaned up easily. I hope this endeavor turns out as well.Comment
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Re: Working on original bulkhead connector
Thanks, Randy! For some odd reason, I never considered that there would be a specific tool for this, but after thinking about it, it's obvious there had to be. I wish I would have known about this 40 years ago. It would have prevented my set of jewelers screwdrivers from learning a lot of bad words over the intervening years.Comment
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Re: Working on original bulkhead connector
Is this tool for removing each pin connector to use on the "ears" of the whole firewall connector?Comment
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Re: Working on original bulkhead connector
From Richard's post, there seem to be 2 "ears" on each connector, therefore a specialized tool would seem to work better than trying to manipulate two tools at once, at least for a fumble-fingers like me. I ordered the Lisle tool (well reviewed on Amazon.com, BTW) and I will let you know how it works out. I really hope I can get by with a simple cleaning, but it's better to be prepared.Comment
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Re: Working on original bulkhead connector
I'm having issues with that connector as well, only it will cause the car to stop running. I've not looked at the connector carefully or cleaned it, but I know that one of the pins is kind of free floating as the plastic that holds it in place has broken. Years ago my father bought a complete wiring harness kit from Eagle Wire Products. I'd say that was at least 10 years ago. My question is, are these reproduction harnesses of good quality? Am I better off repairing the original stuff, or will my car be more reliable if I just change out the harness. I want to keep as much as possible original, but original isn't going to do me much good if I'm stuck on the Cross Bronx Expressway (worst part of living on Long Island is getting off of Long Island).
Thanks.Comment
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Re: Working on original bulkhead connector
John, Disconnect your battery negative terminal, then pull both bulkhead plugs. One will have a #12 Red wire at a connector point, in a corner IIRC. That is usually the culprit for a condition like you're seeing. That supplies power to the car from the main battery feed.
If the housing has melted and caused a loose intermittent connection, you have options.
You can try to repair that terminal connection and plastic housing, made up of 2 Twinlock connector pins,
or you can replace the wire terminals with a spliced-in feed wire,
or you can replace the harness.
As you say, you need to investigate what your problem is, then you can make a better decision for a repair strategy. When you take it apart, if you have capability, try to take some close-up photos for some additional advice.
Rich
p.s. we had a recent thread about those Twinlock pins recently.Comment
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