Loose Electrical Fitting
Thread Starter
Racer
Joined: Oct 2004
Posts: 314
Likes: 0
From: Brooklyn Michigan
Loose Electrical Fitting
I noticed lately that all electrical connections to the car stop working (no dome light, can crank the engine over), no power at all. So I checked the main power feed to the firewall (under the brake master cylinder and sure enough, I wiggle it and all power is restored.
Question: How do I permenatly attach this "bulk head electrical fitting" to the attaching clip on the firewall so it doen't keep coming loose? It seems to be attached by the top and bottom clip, but when slightly moved, it cuts all power. I would hate to be somewhere and have to deal with this inconveince all the time.
What about silicone to hold it in place?
Any ideas?
Tod
Question: How do I permenatly attach this "bulk head electrical fitting" to the attaching clip on the firewall so it doen't keep coming loose? It seems to be attached by the top and bottom clip, but when slightly moved, it cuts all power. I would hate to be somewhere and have to deal with this inconveince all the time.
What about silicone to hold it in place?
Any ideas?
Tod
Le Mans Master
Joined: Apr 2001
Posts: 9,556
Likes: 288
From: Granbury Texas
Tod, my 1967 427 coupe did this brand new in 1967. It happened in traffic when running on the street and highway, often leading to extremelyt dangerous moments (I'm lucky to still be here). My 69 L88 never had this problem, and my 63 has never had this problem. The dealership said the plug contacts came from the factory with corrosion, and after several false tries, they cut the plug off and hand wired in a new firewall plug. I think that today, you would be better to obtain one of the new wiring harnesses and install it. There have been several threads here about harness purchase and installation. I repeat, this can be a serious safety issue, so I would get it permanently resolved before driving it on the road or street.
Safety Car
Joined: Feb 2003
Posts: 4,068
Likes: 27
From: St. Joseph Mo
On the other hand
Mine has never come loose on its own. 
I had it disconnected for the first time last year to clean all the connections and fount it difficult to disengage the locking tabs. It was covered with some undercoating material. Went back together with an audible click(s).
Its possible the undercoating glues the tabs in the locked position.
What shape is yours in? Possibly buggered by Bubba?
I had it disconnected for the first time last year to clean all the connections and fount it difficult to disengage the locking tabs. It was covered with some undercoating material. Went back together with an audible click(s).Its possible the undercoating glues the tabs in the locked position.
What shape is yours in? Possibly buggered by Bubba?
Last edited by 67L36Driver; Jul 24, 2006 at 12:52 PM.
Le Mans Master
Joined: Jan 2002
Posts: 8,913
Likes: 283
It most likely is not coming loose, it is heating up, and creating so much resistance, that it is non conductive. ALso, if you look, if it has been heated, the square plasting housing that contains the main power cable will be melted and distorted. Thus, allowing the metal tang/clip to move around inside of the plug, unable to interface the fuse block contact fully.
Mark
Mark
Le Mans Master
Joined: Jul 2000
Posts: 8,506
Likes: 3
From: Calhoun, GA_______ Let It Rock
I think it is a notorious problem with old midyears. I had a '66 that would do it. Wiggle it and hold my mouth just right and no problem...hit a bump, not hold my mouth right, etc...and it would die at the worse possible time.
3 options...I just replaced the dash harness on my 1965 and the connections, although factory, seem to lock together better.
Bypass it like you said: http://forums.corvetteforum.com/show...head+connector
Clean the contacts, coat with anti-corrosion and give it a try. I wound up using long small bolts (1/4 x 20 ?) with nuts on the other side to keep the connections tight. I think on my '66 that was the problem vs. corrosion.
3 options...I just replaced the dash harness on my 1965 and the connections, although factory, seem to lock together better.
Bypass it like you said: http://forums.corvetteforum.com/show...head+connector
Clean the contacts, coat with anti-corrosion and give it a try. I wound up using long small bolts (1/4 x 20 ?) with nuts on the other side to keep the connections tight. I think on my '66 that was the problem vs. corrosion.
Last edited by Grey Ghost; Jul 24, 2006 at 02:22 PM.
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 4
From: DAVIE/FORT LAUDERDALE FL
Ghostrider is correct. The large red wire gets too hot and over the years that wire in the plastic connector gets loose and breaks contact. It is a poor design-male to male (that never works). The best bet is to replace the harness. Or, I keep a #12 red wire in the glove box that is long enough to go from a battery lug on the horn relay through the firewall and connects to one side of the breaker above the left kick panel. In case of failure, it provides a new source of 12 volts into the car. Once the harness starts getting loose, it will fail more often.
Thread Starter
Racer
Joined: Oct 2004
Posts: 314
Likes: 0
From: Brooklyn Michigan
Thanks for the advice. Went and unplugged the harness from the firewall. Sure enough, the "red" wire was somewhat loose, and there was some light corrosion.
I like the idea of cutting the red wire and sending it through the fire wall. BUT, what do I attache the red wire to then? I looked under the dash, but not sure what to hook it to...can anyone attach some photos? There's like 5 million wires under there and complex wiring is not something I'm good at.
I really want to start doing more work on the car myself, but these jobs scare the hell out of me. If I could only see what to hook the red wire to, I would do it tonight!
Thanks
Tod
I like the idea of cutting the red wire and sending it through the fire wall. BUT, what do I attache the red wire to then? I looked under the dash, but not sure what to hook it to...can anyone attach some photos? There's like 5 million wires under there and complex wiring is not something I'm good at.
I really want to start doing more work on the car myself, but these jobs scare the hell out of me. If I could only see what to hook the red wire to, I would do it tonight!
Thanks
Tod
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Burning Brakes
Joined: Sep 2004
Posts: 1,224
Likes: 49
From: Ventura Calif
After 35 years my 67 did the same thing. I removed the connector, scraped and scrubbed the contacts on the plug and harness, shot it with contact cleaner and put it back together and it works fine. My contacts did show some corrosion.
Drifting
Joined: Sep 2004
Posts: 1,665
Likes: 60
From: Buffalo New York
Tod,
My 66 had a severe case of this very problem. The red wire was the culprit. I had to tie a shoe lace to the harness and pul it tight in an upward direction to make contact. I replaced the engine harness with one from Lectric Limited. It's not hard to do and I have not had an issue since. If you try to clean it up and reinstall you might try some dilectric tune up grease to coat your connections. I use this stuff on my trailer connections and it works great.
Dennis
My 66 had a severe case of this very problem. The red wire was the culprit. I had to tie a shoe lace to the harness and pul it tight in an upward direction to make contact. I replaced the engine harness with one from Lectric Limited. It's not hard to do and I have not had an issue since. If you try to clean it up and reinstall you might try some dilectric tune up grease to coat your connections. I use this stuff on my trailer connections and it works great.
Dennis
Thread Starter
Racer
Joined: Oct 2004
Posts: 314
Likes: 0
From: Brooklyn Michigan
Update:
I completely cleaned both plugs with a small wire brush. The I used electrical contact cleaner on both plugs. Blew dry and inspected. Most (if not all) corroson was gone. Then I used Dialectric grease and reinstalled plug.
The Test:
Well it works A LOT better now, but I can still get the power to cut out if I really work at it by wiggling the plug. I think I'll be o.k. until this winter when I can attache the red wire directly through the fire wall and reconect on the inside.
Question:
Since I can't afford a new wiring harness now, should I remove the fuse block and look for the red wire on the inside? I can't seem to find the main power wire on the inside of the car.
Lastly:
I felt great by starting to do these small jobs myself. I felt very empowered and gain confidence each time I attempt something. Plus, thanks to the great help on this forum!
Tod
I completely cleaned both plugs with a small wire brush. The I used electrical contact cleaner on both plugs. Blew dry and inspected. Most (if not all) corroson was gone. Then I used Dialectric grease and reinstalled plug.
The Test:
Well it works A LOT better now, but I can still get the power to cut out if I really work at it by wiggling the plug. I think I'll be o.k. until this winter when I can attache the red wire directly through the fire wall and reconect on the inside.
Question:
Since I can't afford a new wiring harness now, should I remove the fuse block and look for the red wire on the inside? I can't seem to find the main power wire on the inside of the car.
Lastly:
I felt great by starting to do these small jobs myself. I felt very empowered and gain confidence each time I attempt something. Plus, thanks to the great help on this forum!
Tod
Le Mans Master
Joined: Jul 2000
Posts: 8,506
Likes: 3
From: Calhoun, GA_______ Let It Rock
Loose plugs are a problem with these too. http://forums.corvetteforum.com/show...ght=electrical
Zip tie the plugs to the fuse box and/or Use nuts and washers to help draw them tight.
I don't think the bypass wire would take long to do. You just need to see a wiring diagram or have someone step you through it.
Zip tie the plugs to the fuse box and/or Use nuts and washers to help draw them tight.
I don't think the bypass wire would take long to do. You just need to see a wiring diagram or have someone step you through it.
Last edited by Grey Ghost; Jul 26, 2006 at 02:11 PM.
Thread Starter
Racer
Joined: Oct 2004
Posts: 314
Likes: 0
From: Brooklyn Michigan
Update...Update...Update!
So I decide to keep the ol' girl afterall (the 65'). Wife and I are on our way to work Saturday on the highway and car completely stops running...no electrical power. Pop the hood...jiggle plug, problem solved.
Tonight I decided to go for it. I was sick of having to pay someone to do my work. I removed the fuse block and found the "red" main power wire. I cut it, spliced a lead wire through the fire wall (where a rubber gromet was) and reconnected the red wire where I cut it from the firewall plug.
Had wife come out to garage with fire extinguisher as I reconnected battery. NO PROBLEMS! I started car, checked all lights, radio, antenna, ect... everything worked great! Best of all, no electrical fires
I then jiggled plug while watching dome light, again, NO PROBLEMS! Now I know it may be a "bubba" fix, but I can't afford a new wiring harness now. Thanks to all who gave me the courage and insight to tackle this job myself
It wasn't that hard and I figure I saved myself at least 2 hours labor at a garage. Plus I have the satisfaction of having done it myself.
Tod
So I decide to keep the ol' girl afterall (the 65'). Wife and I are on our way to work Saturday on the highway and car completely stops running...no electrical power. Pop the hood...jiggle plug, problem solved.
Tonight I decided to go for it. I was sick of having to pay someone to do my work. I removed the fuse block and found the "red" main power wire. I cut it, spliced a lead wire through the fire wall (where a rubber gromet was) and reconnected the red wire where I cut it from the firewall plug.
Had wife come out to garage with fire extinguisher as I reconnected battery. NO PROBLEMS! I started car, checked all lights, radio, antenna, ect... everything worked great! Best of all, no electrical fires
I then jiggled plug while watching dome light, again, NO PROBLEMS! Now I know it may be a "bubba" fix, but I can't afford a new wiring harness now. Thanks to all who gave me the courage and insight to tackle this job myself
It wasn't that hard and I figure I saved myself at least 2 hours labor at a garage. Plus I have the satisfaction of having done it myself.
Tod
