Back up light wiring help

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Have removed the transmission cover and see what appears to be wire connections at the base of the gear shifter. Is this where the backup light should be connected? The previous owner had a switch on the dash for the backup light.
 

73FJ40

After another night of rust removal!
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@tlovvorn

Yes. There were two wires, and possibly depending on year, I believe red w/"lavender" (purple or blueish) that went to that switch. They were included in the wiring harness running along the passenger side frame rail.

One of the wires carried power from up front the other went to the light fixture in the back. The light depends on a ground through the frame.
 

Cromagnon

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According to the wiring diagram that I have for a '72 40 series the Back Up Light Switch is supplied from the Fuse Block by a LR wire. The Same color then goes to both of the Back Up Lights at the rear of the vehicle. It has been my experience that the wires are soldered at the switch. Easy to troubleshoot.
 

Living in the Past

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Believe 72s were imported here with both column and floor shift transmissions. On the column shift the switch was at the base of the steering column. On my 68 when I switched to a floor switch I extended the wires to the switch on back of the shifter. Possible someone switched a column to a used floor shifter or more likely the soldered pigtail wires that plug into the harness broke and PO did the easy fix. Had a couple of cruisers the PO installed a push button on the dash for a not working horn button. Seen a number fixes that would qualify for the wall of shame thread. Probably not at top of the of that list but would put this on a list for too lazy to fix it right list.
 
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@tlovvorn

Yes. There were two wires, and possibly depending on year, I believe red w/"lavender" (purple or blueish) that went to that switch. They were included in the wiring harness running along the passenger side frame rail.

One of the wires carried power from up front the other went to the light fixture in the back. The light depends on a ground through the frame.
Thank you for that needed info. Much appreciated.
 
Joined
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Messages
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According to the wiring diagram that I have for a '72 40 series the Back Up Light Switch is supplied from the Fuse Block by a LR wire. The Same color then goes to both of the Back Up Lights at the rear of the vehicle. It has been my experience that the wires are soldered at the switch. Easy to troubleshoot.
My '72 only has one back up light on the left rear of the vehicle.
 

Cromagnon

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My '72 only has one back up light on the left rear of the vehicle.
Then it would only go to one back up light, the wiring diagram I have shows two. There are differences within the same model year and errors in the drawings as well. Not to mention the wonderfulness of Previous Owners!!!
 
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Test the switch pins to see if the switch is working first. Do a continuity test between the pins. Should be no continuity until shift lever is in reverse. If good, then wire it. Makes no difference which pin is the hot wire and which goes to the bulb. Makes no difference what color wire you use.
I know you didn't really ask anything except "Is this where the backup light should be connected? ". ........I offer the above just in case.
 
Last edited:

Cromagnon

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Test the switch pins to see if the switch is working first. Do a continuity test between the pins. Should be no continuity until shift lever is in reverse. If good, then wire it. Makes no difference which pin is the hot wire and which goes to the bulb. Makes no difference what color wire you use.
I know you didn't really ask anything except "Is this where the backup light should be connected? ". ........I offer the above just in case.
Why do you make the statement that it doesn't matter what color wire to use? They could use the WB wire that goes everywhere and make a real PO show out of the wiring, that will solve absolutely nothing. Use the correct color wire for the circuit so that you can troubleshoot the wiring later on when there are other problems. It would be a different story if the wire wasn't readily available but it is, from several sources.
 
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Well, since you asked:
It's two wires. Following them can be done by a 10 year old. Even if doing a Barrett Jackson, you can't see those wires readily. Sometimes when someone is just adding something or rewiring something and they have some wire, they can just use it. If it disturbs you, don't do it. I try not to get upset by those kinds of things. Older vehicle wiring is simple and accessible for observation.
If comments and opinions to a poster are not allowed, let me know.
 
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Joined
May 24, 2020
Messages
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Birmingham, AL
Test the switch pins to see if the switch is working first. Do a continuity test between the pins. Should be no continuity until shift lever is in reverse. If good, then wire it. Makes no difference which pin is the hot wire and which goes to the bulb. Makes no difference what color wire you use.
I know you didn't really ask anything except "Is this where the backup light should be connected? ". ........I offer the above just in case.
Thank you. That is certainly important to make sure it is working first.
 
Joined
May 24, 2020
Messages
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Birmingham, AL
Well, since you asked:
It's two wires. Following them can be done by a 10 year old. Even if doing a Barrett Jackson, you can't see those wires readily. Sometimes when someone is just adding something or rewiring something and they have some wire, they can just use it. If it disturbs you, don't do it. I try not to get upset by those kinds of things. Older vehicle wiring is simple and accessible for observation.
If comments and opinions to a poster are not allowed, let me know.
I appreciate the feedback. Thanks!
 
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Birmingham, AL
I tested the switch and it is bad. Went to AutoZone thinking it was a universal part and when I got it home it is too small to fit. Does anyone know based on my image if this is original with the 72 FJ40? Have a Chevy 350 and not sure if PO replaces tranny as well. Does anyone know where I can get this back up light switch?
 
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Be sure to test it after it's out to be sure it's not the trans actuator that is the issue. Plunger out, no continuity............ Plunger in continuity.
Nothing on your FJ40 is universal :) , everything is way high and "special" :skull:
 
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73FJ40

After another night of rust removal!
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@tlovvorn

IF your transmission is OEM THREE SPEED WITH FLOOR SHIFTER, the switch part no. is as follows:
Switch Assembly Back Up - Toyota (84210-57012) and lists for around $75.

You will also need a crush gasket, part no. 12157-10010 which lists for about $1.64.


These are both available from your local dealer.

Or, if you can wait a month and you trust Indonesian fit and supply quality, $33 and free shipping:


You will still need the gasket from the dealer..
 
Joined
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Messages
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Be sure to test it after it's out to be sure it's not the trans actuator that is the issue. Plunger out, no continuity............ Plunger in continuity.
Nothing on your FJ40 is universal :) , everything is way high and "special" :skull:
I tested it off and still not working. So where can I order a new one?
 
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@tlovvorn

IF your transmission is OEM THREE SPEED WITH FLOOR SHIFTER, the switch part no. is as follows:
Switch Assembly Back Up - Toyota (84210-57012) and lists for around $75.

You will also need a crush gasket, part no. 12157-10010 which lists for about $1.64.


These are both available from your local dealer.

Or, if you can wait a month and you trust Indonesian fit and supply quality, $33 and free shipping:


You will still need the gasket from the dealer..
Thank you!
 
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I have read here on IH8MUD, that some of the switches are opposite of what you need. Yours should be normally open. Some are normally closed for some reason. That will not work for you. Don't know if off shore knows what they are selling. Be careful.
If I had that switch, I would try to take it apart and fix it. That's what I always do. I learn things, nothing to lose and sometimes I fix the part. It would be a very simple switch to fix. The hard part is getting it apart without destroying it. Send it to me if you want me to try. No charge.
 
Last edited:
Joined
May 24, 2020
Messages
32
Location
Birmingham, AL
@tlovvorn

IF your transmission is OEM THREE SPEED WITH FLOOR SHIFTER, the switch part no. is as follows:
Switch Assembly Back Up - Toyota (84210-57012) and lists for around $75.

You will also need a crush gasket, part no. 12157-10010 which lists for about $1.64.


These are both available from your local dealer.

Or, if you can wait a month and you trust Indonesian fit and supply quality, $33 and free shipping:


You will still need the gasket from the dealer..
Just got it ordered! Thank you!
 
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