back up light switch
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Senior User
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back up light switch
The back-up lights on my 79 302/C-6 wont work despite me doing all the usual things like checking bulbs, grounds etc. I wonder if it is the switch itself on the tranny? Costs about 60$ so I dont want to replace it if I dont need to.
anybody have any experience with this thingy? Is it hard to install etc?
thanks
anybody have any experience with this thingy? Is it hard to install etc?
thanks
Posting Guru
Joined: Mar 2001
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back up light switch
I had a similar problem on my '79 with a C4. If you have a manual with the electric schematics, you should be able to check the current going to the switch at the connector next to the firewall. I also jumped my reverse lights to see if the line to back and bulbs were good - just to narrow it down to the switch. $70 seems high, I don't think I paid more than $30 for mine. The switch will should come with the plug. Only pain was finding the right drill to line up the switch correctly. I had to go to a few hardware stores before I found the right letter / size - can't remember off hand what it was. I can check though.
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Joined: Jan 2008
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back up light switch
[updated:LAST EDITED ON 15-Mar-02 AT 10:36 PM (EST)]Beartracks, The neutral safety/back up light switches on 78-79's are on the side of the tranny.
How to test for a bad switch.
Take a test wire(alligator clips on each end).
Attach one end on the + post of the battery and the other to the Back-up light wire Black/Red. The harness is attached to the firewall with a gray connector.
If the B/U lights come on < The switch is bad.
How to clean them up to work again.
Remove them and soak them in varsol for a couple of hours.
Sometimes I use lacquer thinner(it's the best but cold on the hands)
Shake them lots and blow them out with air.
Then use electrical contact cleaner
without hooking them to the transmission plug them into the harness and get a helper to watch when you click the switch.
1/8" drill bit should work.
Need a picture?
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
[i][font color=red]Calgary,Alberta,Canada[/font][i]
[font color=blue]Please Don't Ask Me Any Tough Questions,
"I'm Saving My Memory For When I Develop Alzheimer's" [font/]
78 F-150 429CJ,Silver, Explorer Pkg.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
How to test for a bad switch.
Take a test wire(alligator clips on each end).
Attach one end on the + post of the battery and the other to the Back-up light wire Black/Red. The harness is attached to the firewall with a gray connector.
If the B/U lights come on < The switch is bad.
How to clean them up to work again.
Remove them and soak them in varsol for a couple of hours.
Sometimes I use lacquer thinner(it's the best but cold on the hands)
Shake them lots and blow them out with air.
Then use electrical contact cleaner
without hooking them to the transmission plug them into the harness and get a helper to watch when you click the switch.
1/8" drill bit should work.
Need a picture?
Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg
[i][font color=red]Calgary,Alberta,Canada[/font][i]
[font color=blue]Please Don't Ask Me Any Tough Questions,
"I'm Saving My Memory For When I Develop Alzheimer's" [font/]
78 F-150 429CJ,Silver, Explorer Pkg.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon
Junior User
Joined: Mar 2002
Posts: 50
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From: Hallsville USA
back up light switch
I have changed a couple of these on a couple of different trucks. It seems to be a common problem. It always seems to be some overheated contacts and some melted plastic on the tranny switch, if you take the switch apart.
It's almost as if the switch isn't quite heavy enough to carry the current for the wattage of the bulbs that are installed.
The switch is sort of expensive so I rewired mine so that I wouldn't have to replace it again any time soon.
I took a common 12V relay and wired it so that the switch operated the relay and not the light bulbs. This decreased the current that the switch had to carry.
I wired the lamps across the normally open contacts of the relay. They are pretty heavy contacts and have no problem carrying the load. I shouldn't have to replace the switch again for a very long time.
If you are interested in this mod, I can look up the wire colors and plug locations for you. It's really a pretty simple mod.
It's almost as if the switch isn't quite heavy enough to carry the current for the wattage of the bulbs that are installed.
The switch is sort of expensive so I rewired mine so that I wouldn't have to replace it again any time soon.
I took a common 12V relay and wired it so that the switch operated the relay and not the light bulbs. This decreased the current that the switch had to carry.
I wired the lamps across the normally open contacts of the relay. They are pretty heavy contacts and have no problem carrying the load. I shouldn't have to replace the switch again for a very long time.
If you are interested in this mod, I can look up the wire colors and plug locations for you. It's really a pretty simple mod.
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Senior User
Joined: Mar 2001
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back up light switch
Paid $60 for mine and the switch was the problem. Be careful with the 3 bolts that hold the switch on as I broke two heads off. Take your time with the alignment and everything should run smooth. If all you want to do is have back up lights then you could always run a switch through your dash and save the $60 for gas money. Just my two cents. Good Luck.
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Senior User
Joined: Nov 2001
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back up light switch
thanks everyone. Do the bolts tend to seize because it doesnt look that easy to get at, and if a bolt is even thinking of breaking, it makes its mind up when it sees me coming! I am going to take the damn thing off and try to clean it up. And just bought 79 parts truck with the C6 so I have an extra when I smash the first one because of my notorious lack of patience with certain Ford better ideas!