P15 Backup Light

[Drdialtone]

I've found a backup light off a 46-48 Plymouth that I would like to add to my car.  Is there a switch that is activated when the trans is put into reverse OR did they have a aux switch to turn on and off?  Thanks!

[DonaldSmith]

I think the backup light was usually controlled by an auxiliary switch, at least for the postwar Mopars.

 

I rigged up a switch at my shifting linkage under the hood.  Since there is no "First gear", with the semi-automatic, pulling the gearshift lever toward the driver activated the switch.  If it were a stick shift, I would need another switch for gearshift "up" only, and wire the switches in series so both switches would have to be on to work the backup light.

 

With my steering column alterations, I'm going to put the backup a switch at the transmission.  That will be a challenge. 

[Ulu]

You don't need an internal trans switch to have backup lights. You just need a switch somewhere on the linkage which activates in reverse. Any modern pedal type brake light switch could be used

[Eneto-55]

Old thread, but possibly best place for my comment.

 

I see that starting with the P17 & 18 (1949 second series), the transmission has a threaded hole on the left side of the transmission for a back up light switch.  I do realize that there are other ways to get this going on the P15 & earlier cars, but just wondering if anyone has drilled & tapped their P15 trannie to take the backup light switch?

Edited November 28, 2019 by Eneto-55

[allbizz49]

2 hours ago, Eneto-55 said:

Old thread, but possibly best place for my comment.

 

I see that starting with the P17 & 18 (1949 second series), the transmission has a threaded hole on the left side of the transmission for a back up light switch.  I do realize that there are other ways to get this going on the P15 & earlier cars, but just wondering if anyone has drilled & tapped their P15 trannie to take the backup light switch?

Too bad you aren't closer to me. I'd give you the 3 speed out of my 49. Went with a t5 and the original tranny is just taking up trunk space.

[Eneto-55]

26 minutes ago, allbizz49 said:

Too bad you aren't closer to me. I'd give you the 3 speed out of my 49. Went with a t5 and the original tranny is just taking up trunk space.

Thanks, but yeah, that's a long ways.  My brother (in Oklahoma) has one out of a 53 Cranbrook, but I don't recall if it had backup lights, or not.  I reckon, though, that the transmission would have had the threaded hole, even if it was just plugged.  I had to crawl under my car to see if I had the hole or not, because my engine is out of a 55 model (came with the car - as a basket case - when I bought it).  I thought I might actually have a later transmission as well, but it must be the original.

I was just working on scanning my Plymouth manual last night when I just happened to notice that diagram.  (The manual covers P15, P17 & 18, and P19 & 20; that is, 46 - 1st series 49, 49 2nd series, & 1950.)

 

Edited November 28, 2019 by Eneto-55

[Eneto-55]

On 11/28/2019 at 1:48 PM, Eneto-55 said:

Old thread, but possibly best place for my comment.

 

I see that starting with the P17 & 18 (1949 second series), the transmission has a threaded hole on the left side of the transmission for a back up light switch.  I do realize that there are other ways to get this going on the P15 & earlier cars, but just wondering if anyone has drilled & tapped their P15 trannie to take the backup light switch?

 

Pushing this question back up, since no one has said yay or nay.  Still curious about the internal activation of the transmission-mounted backup light switch, whether the mechanism which activates it is something that is already a part of the earlier model transmission (i.e., P15), or if the internals on the later model transmissions were different.

 

Also, how is the backup light wire routed down to the switch?  Through the firewall, then down?