Fuse Panel - Engine Bulk Head Connectors

[Al P.]

On my 67 I am trying to unplug the the inner bulk head connector (the one closest to the engine) to check connections, with the tabs depressed I can't remove the connector, it seems to be pulling the entire bulkhead (both sides - male - female connectors - the pair) connector and won't break free.

I do not want to damage the fuse panel wiring by pulling this thing too hard.....

Could it be cuz both if the bulk head connectors (there are 2 of them under the master cylinder) must be pulled apart together and not one at a time. Im stumped? They havent been separated in like 35 years!

Has anyone ever had this problem?
Any suggestions to get them unplugged?

[Erich C.]

Re: Fuse Panel - Engine Bulk Head Connectors

The two connectors interlock but first you have to unscrew the retaining bolt.
It is in the center and is probably covered with sealer. The bolt has a retaining ring clipped to it on the inside of the one connector. It will not just unscrew and pull out. When you start to unscrew the bolt you should see the connectors start to move away from the firewall. IIRC the bolt has a 3/8" head on it.
Erich

[John H.]

Re: Fuse Panel - Engine Bulk Head Connectors

The two connectors interlock but first you have to unscrew the retaining bolt.
It is in the center and is probably covered with sealer. The bolt has a retaining ring clipped to it on the inside of the one connector. It will not just unscrew and pull out. When you start to unscrew the bolt you should see the connectors start to move away from the firewall. IIRC the bolt has a 3/8" head on it.
Erich

Erich -

There's no center connector bolt on a '67 fuse block - that design didn't start until '68 or '69.

Al -

Keep working on it, but be patient - it WILL come apart.

[Michael G.]

Re: Fuse Panel - Engine Bulk Head Connectors

Al, I came across the same problem tonight. Both of my connectors likely had not ever been removed in 45 years. I knew that I would to overcome some friction, but without tugging on the connectors very hard. I got one side of the first connector free first by pushing down on one of the plastic retaining clips, slipping the connector over it, and working the connector back and forth until it slipped over the other clip. I even pushed the connector back to the fully locked position several times to try to gain just a little additional movement the next time I unlocked one side of it. Also, I had to pry gently on the edge of the connector with a long screwdriver to increase the amount of movement once the connector was free of one of the clips and then depress the other plastic retaining clip fairly snugly. At one point, I pushed the clip down with the end of a screwdriver blade with my left hand and moved the connector with my right hand to overcome the friction of the pins. Sort of a contorted position, but using two hands proved to be the successful approach for me. Eventually the connector became loose enough to slide over the remaining clip and off the pins. Just have to work things back and forth a very little bit at a time and be very gentle so you don't break or bend anything. I took a few short breaks to rest my fingers and evaluate what approaches would work better in my next attempt. Took me about an hour, working very slowly and patiently, to remove both connectors.

[Al P.]

Re: Fuse Panel - Engine Bulk Head Connectors

Al, I came across the same problem tonight. Both of my connectors likely had not ever been removed in 45 years. I knew that I would to overcome some friction, but without tugging on the connectors very hard. I got one side of the first connector free first by pushing down on one of the plastic retaining clips, slipping the connector over it, and working the connector back and forth until it slipped over the other clip. I even pushed the connector back to the fully locked position several times to try to gain just a little additional movement the next time I unlocked one side of it. Also, I had to pry gently on the edge of the connector with a long screwdriver to increase the amount of movement once the connector was free of one of the clips and then depress the other plastic retaining clip fairly snugly. At one point, I pushed the clip down with the end of a screwdriver blade with my left hand and moved the connector with my right hand to overcome the friction of the pins. Sort of a contorted position, but using two hands proved to be the successful approach for me. Eventually the connector became loose enough to slide over the remaining clip and off the pins. Just have to work things back and forth a very little bit at a time and be very gentle so you don't break or bend anything. I took a few short breaks to rest my fingers and evaluate what approaches would work better in my next attempt. Took me about an hour, working very slowly and patiently, to remove both connectors.

Wow - Which one came off first? Or did they come off together? I'm afraid I'll pull apart the wiring on the back side of the fuse panel (that's what mine feels like when pulling - They are not budging.... How did the pins look on both connectors when you finally got them apart? Any problems?

[William C.]

Re: Fuse Panel - Engine Bulk Head Connectors

Those terminals are referred to as a "twinlock" design, as the identical terminal is used on both the engine and passenger side of the connection. They are small and somewhat fragile, but using the procedure Michael described, they can generally be coaxed apart successfully. One tip is to press inward from the engine side to help loosen the terminals as well as pulling outward.

[Michael G.]

Re: Fuse Panel - Engine Bulk Head Connectors

Al, I worked with the driver's side connector first. I worked to get the driver's side clip of that connector released first, pressing alternately with my finger and a flat screwdriver tip. I continued to work the entire connector in and out, even though it moved only a little. When the driver's side clip came loose, the connector was still connected via its passenger side clip. I moved the connector in and out, back and forth to overcome the pin friction. I pushed the entire connector back onto its original position with its driver's side clip re-engaged. I tried not to tug on the wires, just the connector. Then, I unlocked the driver's side clip and started moving the connector again, while pushing down on the passenger's side clip firmly with my finger. I know that I had to use a screwdriver gently to continue to pry against the connector's at times, but did this very gently. Eventually, the connector popped loose from the passenger's side clip. The pins looked corroded with age, not the classic electrical corrosion that you see atop battery terminals. So, I will probably clean them with some appropriate electrical solvent.

There should be 2 screws holding the panel to the firewall. One is on the top right of the panel as you look at it, and the other is hidden under the bottom left fuse. You should be able to see their threaded ends sticking through the firewall. If you don't have either of these in place, I would guess that the panel would not feel firm against the firewall. You probably should put a long, thin bolt and secure it with a snug, but not too tight, nut through any holes missing screws to ensure that the panel is tight against the firewall while you are working.

The passenger's side connector was a little more challenging. I was able to get its driver's side clip loose like I did with the driver's side clip on the driver's side connector as described above. Then, more moving the passenger's side connector in and out, back and forth, reconnecting the driver's side clip of this connector, then loosening it. Also, I had to use a screwdriver gently again to work and pry in any direction I could to overcome pin friction. The toughest part of the entire drill was to remove the passenger's side clip on this passenger side connector once the connector was moving fairly freely. I ended up using both hands--screwdriver in my left hand pushing down on the clip gently, but firmly, with the flat end of the screwdriver while my right hand tugged on the connector, not the wires. In and out, back and forth motion again helped to reduce the pins' friction. I had to take several breaks as this really contorted all of my upper body joints to get the connector to come loose. My biggest challenge was restraining my effort so that I did not break anything and have subsequent hardware or electrical problems. I had to apply gentle, but firm force throughout all of this. Once one of the clips comes loose, you start to have the confidence that this job can be done with effort and time.

The pins on the passenger's side connector were similarly corroded with age as the driver's side connector and will require the same treatment with electrical solvent.

I did not use any kind of lubricant to reduce the pins' friction once either of the connectors started to move a little. Maybe spraying a little electrical solvent onto the pins might help unfreeze them without causing electrical problems when you reconnect the connectors.

I hope that my experience helps you. If you are still having trouble, please call me in CO at 719-531-7408, and we can talk about your specific challenges.

[Al P.]

Re: Fuse Panel - Engine Bulk Head Connectors

Thanks Michael for the very informative response. Thanks to all as well. I'll give it another shot soon.

[Al P.]

Re: Fuse Panel - Engine Bulk Head Connectors

Well today I very carefully removed the bulkhead connectors, and they disconnected very easily (within 5 mins) - The lock tabs had to be pushed in more tightly.

So I'm fighting my high ammeter reading issue and the first pin on the left bottom of the inner bulkhead connector has corrosion on both pins of the fuse panel connector. I think that is the 12V lead supplying power to the interior of the car. Yes?

So my next step is to clean all 4 connectors pins and reconnect....

How do you remove the corrosion and clean all pf the pins?

I do have electronic connector spray that you put on after the pins are cleaned.... Thanks!

[Michael G.]

Re: Fuse Panel - Engine Bulk Head Connectors

Al, good work getting the connectors / terminals apart.

For your first question about the 12V lead supplying power to the interior of the car, I don't know. You would have to look at a wiring diagram. Unfortunately, that part of the diagram in my AIM is rather faint, and I would not want to advise you based on a guess.

However, when you ask about cleaning the connectors, if there is corrosion like the chemical buildup on the top of your battery terminals, you could carefully use a small, clean, soft brush or toothbrush and a small supply of water and baking soda to remove the buildup. But apply it very gently. Then, dry things it out thoroughly with low pressure compressed air and spray both male and female sides with an electronics cleaner solvent. If your corrosion is due to age like mine seemed to be and would be more aptly described as discoloration, I used only the electronics cleaner solvent on both male and female sides and plugged them back together.