72 coupe, backup lights electrical
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
72 coupe, backup lights electrical
I have power at the fuse block but no power at the switch on the transmission. I pulled the plug apart at the firewall and with the car on and in reverse no power on either the pink nor the green plug. I went underneath the dash and I have power on the fuse block at the backup lights terminal..... then isn't this where the pink come off and goes up through the wire harness to the firewall? All other lights inside and outside work. Blinkers and brights and brake lights all work... this is all that I have left to fix on the electrical side. Any ideas??? from what i understand the pink from the fuse box provides the constant power and then the switch on the trans, when activated, connects the pink and green sending power to the back up lamps... am I right? I really dont want to pull the dash apart again but I am fearing i will have to...
1972 coupe, 4spd, small block, with A/C
thanks in advance...
Sully
1972 coupe, 4spd, small block, with A/C
thanks in advance...
Sully
Last edited by Sully1882; Sep 8, 2008 at 12:46 PM. Reason: added better detail
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I have power at the fuse block but no power at the switch on the transmission. I pulled the plug apart at the firewall and with the car on and in reverse no power on either the pink nor the green plug. I went underneath the dash and I have power on the fuse block at the backup lights terminal..... then isn't this where the pink come off and goes up through the wire harness to the firewall? All other lights inside and outside work. Blinkers and brights and brake lights all work... this is all that I have left to fix on the electrical side. Any ideas??? from what i understand the pink from the fuse box provides the constant power and then the switch on the trans, when activated, connects the pink and green sending power to the back up lamps... am I right? I really dont want to pull the dash apart again but I am fearing i will have to...
thanks in advance...
Sully
thanks in advance...
Sully
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Sully I'm going 6 diff. directions now and dont have a diag. to look at but go over to your turn signal flasher and see if you have a double wire on 1 terminal.I think thats where your pink for the rev. switch originates or Ts in.Make sure you dont have an issue there.
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
sully
Racer
Joined: Aug 2007
Posts: 323
Likes: 0
From: CA
I have power at the fuse block but no power at the switch on the transmission. I pulled the plug apart at the firewall and with the car on and in reverse no power on either the pink nor the green plug. I went underneath the dash and I have power on the fuse block at the backup lights terminal..... then isn't this where the pink come off and goes up through the wire harness to the firewall? All other lights inside and outside work. Blinkers and brights and brake lights all work... this is all that I have left to fix on the electrical side. Any ideas??? from what i understand the pink from the fuse box provides the constant power and then the switch on the trans, when activated, connects the pink and green sending power to the back up lamps... am I right? I really dont want to pull the dash apart again but I am fearing i will have to...
thanks in advance...
Sully
thanks in advance...
Sully
My 74 diagram shows a hot wire from fuse block to flasher. Off that termial a Pink wire to
backup sw. A lt gr wire back to backup lights but it goes to a termial block first.
I can e-mail you it if you want. PM glassman74
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
thanks,
Sully
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Yeah, I will take you up on that email, sully1882@aol.com. So is the flasher behind the passenger side lower dash panel? I keep thinking that is where it is....
thanks,
Sully
thanks,
Sully
Silly question but did you check your ground for the backup lights?
cc
Last edited by CCrane65; Sep 8, 2008 at 10:43 AM.
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Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
thanks again ,
Sully
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
no i never even made it that far back .... i just figured since there was no power at either the pink nor the green at the firewall that had to be fixed first... SHouldn't the pink always be hot with the car on and the green and pink become hot when the car is in reverse. I tested it both ways, car is still up on jacks, and got no power on pink or green either way...
thanks again ,
Sully
thanks again ,
Sully
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If you want to apply 12 volts to the green wire with the switch in the OPEN position you can do so and see if the rev. lights light HOWEVER dont do it with the switch closed OR apply the 12 volts to the pink UNTIL you find the other end of the pink and why its not hot.did that make sense? (not knowing if the pink is grounded or something else.)
Racer
Joined: Aug 2007
Posts: 323
Likes: 0
From: CA
Yeah, I will take you up on that email, sully1882@aol.com. So is the flasher behind the passenger side lower dash panel? I keep thinking that is where it is....
thanks,
Sully
thanks,
Sully
Sent you e-mail w/wiring. glassman74
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
If you want to apply 12 volts to the green wire with the switch in the OPEN position you can do so and see if the rev. lights light HOWEVER dont do it with the switch closed OR apply the 12 volts to the pink UNTIL you find the other end of the pink and why its not hot.did that make sense? (not knowing if the pink is grounded or something else.)
Im curious now for sure....
thanks again,
Sully
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
I know it sounds like a silly question, but do you have 12 volts on both sides of the fuse at the fuse block? You still haven't said 4 spd or auto, but the 4 spd should have a connector plug on the engine side of the firewall near the driver's side valve cover. Can you follow the pink wire up to see if maybe it's burned by the exhaust? If the negative on your meter is grounded, you should have 12 volts on the pink regardless of what's happening at the b/u lights and grounds in the rear (if the ignition is on)
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
I know it sounds like a silly question, but do you have 12 volts on both sides of the fuse at the fuse block? You still haven't said 4 spd or auto, but the 4 spd should have a connector plug on the engine side of the firewall near the driver's side valve cover. Can you follow the pink wire up to see if maybe it's burned by the exhaust? If the negative on your meter is grounded, you should have 12 volts on the pink regardless of what's happening at the b/u lights and grounds in the rear (if the ignition is on)
thanks,
Sully
Thread Starter
Melting Slicks
Joined: Feb 2006
Posts: 2,092
Likes: 5
From: Fayetteville Arkansas
man... if only i didn't have to work and was at home.... lol.... so much progress could get done....it's frustrating when you have all these ideas of what could be wrong and what could be checked but can't until you get back home after the day is done...
I need to win the lottery or something...
I need to win the lottery or something...
Team Owner
Joined: Jul 2006
Posts: 22,162
Likes: 4,171
From: Kannapolis NC
If putting 12 volts on the wire at the firewall connector makes your b/u lights work, run another wire from the b/u fuse to the connector and bypass the bad wire. Really any switched 12 volt source will work.You'll probably find a broken wire or connection, at least it's not a long distance between them.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
If putting 12 volts on the wire at the firewall connector makes your b/u lights work, run another wire from the b/u fuse to the connector and bypass the bad wire. Really any switched 12 volt source will work.You'll probably find a broken wire or connection, at least it's not a long distance between them.
Melting Slicks
Joined: Mar 2002
Posts: 2,140
Likes: 7
From: Ohio
That wire comes through the firewall as two wires on a four speed and not the way other wires do. I would look for the wire to be broken near the firewall. You could pull it back inside to check it out for breaks and where it hooks into the wireing.