Undercarraige and Bed Lights

Bear Hunter

JAKD 07 Harley
Joined
Apr 24, 2006
Messages
281
Got a few inquiries on how this MOD is done....

First and foremost credit for the Undercarraige Lights and Wiring goes to DrSpeed.


UNDERCARRAIGE LIGHTS:

You want to make sure that you get fogs that throw light everywhere. Cheap fogs usually accomplish this very well due to the fact that they are cheap and do not have a focused beam.

Under the door sill inside the cab, look for the black wire w/blue tracer. that's your dome light signal.

Here's how to connect the proper poles to your relay.

# 85 of black w/blue tracer (DOME LIGHT WIRE)
# 86 goes to ground
# 30 fused power
# 87a to lamps

I mounted the relay on the firewall: (you can mount it wherever you want)

PIC of the light...its aimed to shoot accross to the other side of the truck inbetween my AMP steps: Wiring threaded behind the sill:

13785.jpg


Pic of the lights on: They are activated when...

a. The door is opened
b. When you unlock your doors using the key FOB
c. When you turn on your dome light inside the Cab

13786.jpg


The lights were about $20.00 (AUTOZONE)
The extra wire, relay, connectors, self tapping screws, shrink tube, plus some misc stuff I didn't have handy = $20.00



BED LIGHTS:

I picked up some really small 55 watt fog lights from Walmart for $19.00. Here is a pic of the box with cellphone for reference.

13805.jpg


The first issue was how to maximize the light output throughout the bed using only two lights. After playing around with it I found that mounting them sideways enabled me to aim them at opposite corners at the front of the bed. The wiring is hidden through a factory hole and routed through the tailight and down the frame to a relay that I already had for my undercarrage lights up by the firewall.

Based on DrSpeeds formula all I needed to do was install a 30 amp fuse (on the relay used for the undercarriage lights) to enable me to run both the undercarrage and bedlights without overloading anything.

*** Run a separate power wire for the bedlights to the relay used for the undercarriage lights. Remove the power wire for the undercarriage lights at the relay and crimp both power wires (undercarriage and bedlight) to a single spade and reinstall on the relay ***

…Ok that establishes power to one of the bedlights…all you have to do now is tap into the power wire to that light for the second one. Make sure you ground both lights.

Close up of the light mounted in the corner: You can see all the wiring goes through the factory hole and through the tailight eliminating any visible wires.

13797.jpg


You can see by the light pattern that they are aimed to opposite corners to maximize light output (Shown with Retrax Bed Cover Closed)

13798.jpg


Another pic with bed open with undercarrage lights:

13804.jpg


The Bed lights are activated when...

a. The door is opened
b. When you unlock your doors using the key FOB
c. When you turn on your dome light inside the Cab
 
Nice writeup BH. I use those little fogs (ones with the phone) on my Jeeps undercarraige for offroading. They're bright little fockers... I guess I'm going to get this one going, maybe tomorrow while I'm tackling some of the other things.
 
Those lights look awesome. I really want to do this, but I'm retarded when it comes to electrical wiring unless it is spelled out for me. What kind of relay are you using and do you have a picture of it. Just to make sure, you are only using two flood lights right? The 85, 86, 30 and 87a, are those the numbers that are labeled on the relay? Sorry if these are elementary electrical questions but I just want to make sure i do it right.
 
StrokerAce said:
Just to make sure, you are only using two flood lights right?

Unless I'm mistaken, he's using two small fog/flood lamps in the bed and the two that are just a tad larger under the truck.

StrokerAce said:
The 85, 86, 30 and 87a, are those the numbers that are labeled on the relay?

Those are the numbers on the relay. They have relays for different load requirements, just get one for a 30A load and wire it in as he mentioned and have fun with it. :rockwoot:
 
Yep sredish got you covered:

The relay is a simple Bosch type that looks like this
bosch_relay02.jpg


basicrelay.jpg
 
I like that yellow visual. Nice and to the point, yet you don't have to write it all out yourself.... :)
 
Thanks for posting the diagram, it makes alot more sense now but I have another question. The fused power that goes to number 30, is that going to be a fused power lead directly from the battery or is that going to tap into the fuse block.
 
Hey Bear... I just have one more question. Did you use a relay for each set of lights or just one for all (4) lights?

<<< Rookie...LOL
 
Last edited:
My understanding is that it was one relay but he had to up the fuse in the 30/51 part from the battery to a 30 amper from something else.
 
Sweet! now the rest of my lighting problems have been solved. I have added cab lights and pinch weld lights. I have been looking for a solution to inbed lights. I also like the undercab lights. This will give the guys at work something else to f*** with me about. They claim my truck is lit up like an 18 wheeler. This is a real sweet use of those two biga** batteries under the hood! Thanks BH!

BTW, did anyone ever find your last truck? I always looked on I-10, never saw a beaner driving it!
 
Great Idea! I've had them for two months now and everyone thay sees them light up my bed asks if truck came with them. I say no, and it's easy to do. I'm not telling the secrets and the install tecniques though!
 
is there a way with this relay to run another power wire to it on a switch to be activated with out it turning the interior light and what not on??
 
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