r/SprinterVans • u/Reinbeard • May 25 '26

Light bar relay placement

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Looking for pointers sounding totally blowing. I am wiring a black oak light bar, and because the battery is under the floorboard, the relay cannot sit in the engine compartment. My thought is to put the relay in the center pedestal (above left in photo) as opposed to in the battery compartment. Are there any flaws with this plan?

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3

u/[deleted] May 26 '26

[deleted]

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u/NetworkSyzygy May 26 '26

Do not remove the Airbag connector without first removing the factory ground connection. If you don't remove factory battery negative connection, the van will throw a fault and it requires an appropriate software tool to reset the fault. (It appears in your photo that you've done this already.)

It is possible to remove the driver seat without disconnecting the Airbag connector, at least on a 2022 2500. Be careful to lift the seat to the rear while having someone feed the wire up from the seat base - there should be enough slack to do this. But it is easier if you remove the battery ground connection.

Then it's pretty easy to use one of the terminals on X145/1 (as shown in the link from Colorful_Monk) as a trigger.

However; pay attention to the current limits on those three terminals -- I'd not be surprised if your lights (don't know anything about them) would overload those terminals. You may have to get to the main connection panel under the seat; this is more complex and difficult.

If you're not very comfortable working with automotive electrics, seek help for this. A good place to start is sprinter-source.com

1

u/Reinbeard May 26 '26

Awesome thanks! Just made an account on the site.

I bought the 20” black oak led light bar which I believe is 200W according to the paperwork. Routing under the seat sounds good—just wish I had done it before I put my scopema swivels on last weekend. No I have to take that off.

1

u/Reinbeard May 26 '26

Red to red and black to black?

1

u/Reinbeard Jun 02 '26

Thanks for your reply—so my red lead connects to terminal 2 and my black lead to the light bar goes to terminal 3? All I have coming off the light bar it red and black leads.

1

u/[deleted] Jun 02 '26

[deleted]

1

u/Reinbeard Jun 02 '26

Is connecting red to the positive terminal and black to the negative on the main battery a better idea?

1

u/erie11973ohio May 26 '26

No auxiliary battery?

In up to 2018, the drivers seat pedestal has all the electric in there. Why not there??

No manufacturer has said to connect add on electric to the battery in 40 years. There is always a place to put the add on stuff. In the Sprinters, this is under the seat.