g741.org

I have a 24v linear LED fixture that I want to use as a cab light in my M43. How and where should I wire it in so that I can turn it on/off anytime?

Thanks,
Justin

I'd suggest installing it on the bulkhead above the access hatch to the rear compartment so that it would serve as a dome/map light. Just wire in an extra ignition switch (appropriate labeled, of course) on the dash and you're good to go.

Thanks Lifer,
There's actually already a great space for the light where the roof slopes to meet the top of the windshield frame; there's a small upturned channel that the light can sit in and be completely hidden.
But what I really need is info about how to wire it in. Where would be a good place to make the splice? I am hoping I can find/make a simple 2:1 Douglas adapter to tap power off somewhere under the dash so I can turn the light on with the truck off if needed.
I have a wiring diagram already.

Thanks again!

Have you considered just tapping into an existing wire with a Scotch-Lok connector?

The best place would be the wire that feeds your ignition switch if you want to be able to turn the light on while the truck was shut off.

Since it is a dome light of sorts, I'd try to wire it into the #38 circuit between the circuit breaker and the back dome & surgical lights. The schematic shows a couple of connectors (vic 38-38A & 38A-38B) prior to the surgical lamp so if there isn't already a double Douglas connector feeding something else, one of those may be a good place to add one. I like the idea of the double Douglas connector so that it could be removed easily if needed keeping it more original in appearance.

Lifer wrote:Have you considered just tapping into an existing wire with a Scotch-Lok connector?

The best place would be the wire that feeds your ignition switch if you want to be able to turn the light on while the truck was shut off.

thanks again Lifer,
before the ignition switch was my first thought. I want to see if I can use Douglas connectors to grab power so I can choose to remove it all later.

best,
Justin

mike_l wrote:Since it is a dome light of sorts, I'd try to wire it into the #38 circuit between the circuit breaker and the back dome & surgical lights. The schematic shows a couple of connectors (vic 38-38A & 38A-38B) prior to the surgical lamp so if there isn't already a double Douglas connector feeding something else, one of those may be a good place to add one. I like the idea of the double Douglas connector so that it could be removed easily if needed keeping it more original in appearance.

great idea Mike, I'll check out that circuit. I would assume it's a hot circuit since I imagine they'd want use of those lights even with the truck off.

thanks,
Justin

Saturn surplus has several type piggy back adapter sets available in the metal Douglas and rubber Packard connectors. The instrument spiders also make nice circuit add-on units. They have a nice selection of auxiliary switches as well.

cuz wrote:Saturn surplus has several type piggy back adapter sets available in the metal Douglas and rubber Packard connectors. The instrument spiders also make nice circuit add-on units. They have a nice selection of auxiliary switches as well.

I was eyeing their spider harness with that very thought in mind. I got one earlier to replace the original spider and it's great. Reasonable price too

I would splice in after the ignition switch, that way, when you shut the power off on the truck, the light will shut off as well... if your missus is anything like mine, she will turn it on, and leave it on every time she rides with you, which will result in lots of dead batteries and frustration. Wiring it in on the switched side of the ignition switch will prevent this.

Josh wrote:I would splice in after the ignition switch, that way, when you shut the power off on the truck, the light will shut off as well... if your missus is anything like mine, she will turn it on, and leave it on every time she rides with you, which will result in lots of dead batteries and frustration. Wiring it in on the switched side of the ignition switch will prevent this.

Hi Josh,
Thanks, I may do that, but I already have a battery disconnect switch installed and am maniacal about using it!

Justin

Do you have the spotlight? There is already a wire that runs to it that would be perfect to use or to go with the double connector for both. The spotlight wire should feed off the wiring harness that will be behind the sheet metal pieces on the right side of the cab.

Glenn wrote:Do you have the spotlight? There is already a wire that runs to it that would be perfect to use or to go with the double connector for both. The spotlight wire should feed off the wiring harness that will be behind the sheet metal pieces on the right side of the cab.

Glenn,
That's an excellent idea and yes I do have the spotlight. That will make things a lot easier, but where to put the switch? My linear LED strip is slightly shorter than the width of the channel it will sit in so perhaps I can source a tiny switch to fit in along side it. Appreciate the input!

What about a door actuator switch, they can be had at car alarm shops, I think?
I have a pair I'm planning on using on of these days, you drill a pilot hole and thread them in. I take a pic for you tomorrow afternoon.

m-37Bruce wrote:What about a door actuator switch, they can be had at car alarm shops, I think?
I have a pair I'm planning on using on of these days, you drill a pilot hole and thread them in. I take a pic for you tomorrow afternoon.

thanks Bruce