Modified Reverse Light Switch for Toybox users

[BamaBleach]

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So this weekend I started my Marlin Toybox install and made some modifications to my reverse light switch (for my H42) so I could still use it.

For those that don't know, the switch is too long and interferes with the toybox. Most people plug the hole and wire up a toggle switch for their reverse light. I really didn't want to do that so we decided to see if we could shorten up the switch. It takes a bit of time but we came up with a pretty easy solution.

Step 1: Put the switch in a vice and carefully cut through the outer metal casing of the switch with a cut-off wheel. This will allow you to open up the "guts" of the switch.


Step 2: Pull the plug apart.


Here's what you should have (you can see the excess casing around the yellow wires):

[BamaBleach]

Step 3: Next we trimmed the bottom post so we could connect the wire to the bottom of the plug instead of the back:


Step 4: Trim the other post and cut grooves so the wires will have a place to rest when you go to solder them back:


Step 5: Check your clearance

[BamaBleach]

Step 6:  Solder the wires back on




Step 7:  Do a Continuity test to make sure you did a good job soldering the wires back (use a standard volt/amp meter)

[BamaBleach]

Step 8: My switch had a spacer that I removed to give me extra clearance. Measure the spacer + the amount of metal casing you trimmed off. You will need to trim that much off of the metal plunger.

This is important because the way my switch worked is:
Neutral/Forward gears and light off = plunger depressed
In Reverse and light on = no force on the plunger

So when we trimmed the switch and removed the spacer, this allow the plunger to "sit" further up into the transmission. To ensure that it functioned properly, we trimmed that much off the front of the plunger.





Step 9: Trim the plunger

[BamaBleach]

Step 10: Put the shortened switch back together and install it. Run the continuity test again but this time do it while shifting in and out of reverse instead of depressing the plunger by hand. The first time we had to take it back apart and trim a little more off the plunger because it had force on it in the reverse position. Also make sure you apply force to the back of the switch to make sure the black section is not "riding back out". Just apply pressure to the back of it with your thumb while running the test.


Step 11: I apologize in advance for not having a picture of this step. To ensure that the back portion doesn't "ride out", use a cut-off wheel and make the circle a polygon. You just need a few straight sides so you can take what's left of the metal casing and bend it over the edge with a punch. Same thing you would do to a stake nut (only backwards).

Step 12: Put the boot back on and move on with your toybox install

[BigMike]

Very nice write-up! I've added it to our main site's tech section!

[BamaBleach]

Very nice write-up! I've added it to our main site's tech section!

Very cool.  I'm documenting the whole toybox build and I'll post it up once I'm finished.

[the dude]

Cool mod Bama!

I know this might be hard for you guys south of the border to find:



It's the switch out of a CDM BJ70  It came off the 5spd with split case behind the 3B

Works like a charm.

[BigMike]

Hey dude,

That is a good idea however all of the low profile switches we've seen like that operate on a normally open circuit, whereas the stock Cruiser plug is a normally closed switch.

Can you verify your switch is a closed circuit when it is removed from your transmission and resting on your bench? We have a H42 transmission from a 1985 FJ60 here with an identical looking plug as yours, but it is a normally open circuit when the switch is simply resting on the bench.

Also, can you get a picture of your transmission for me? Thanks

BigMike

[the dude]

It is a normally open switch,  but so was my original switch out of my BJ40.  Maybe it's a diesel thing.

The transmission is an H41 out of a JDM BJ40