wiring in under hood light

[jeeptorino68]

how can i tie this into the stock dome light system. i want to tie the underhood light into that circuit because of the 8 minute safety timer. if the interior lights are on more than 8 minutes they are shut off to save the battery, and i want the same for my under hood light incase the gravity switch it has fails while the hood is shut. any info or ideas on where to tap into this?

 

[Billwill]

how can i tie this into the stock dome light system. i want to tie the underhood light into that circuit because of the 8 minute safety timer. if the interior lights are on more than 8 minutes they are shut off to save the battery, and i want the same for my under hood light incase the gravity switch it has fails while the hood is shut. any info or ideas on where to tap into this?

Looking at the 2002 KJ circuit diagrams....the dome lights get their +12 volts from fuse 34.

That will not help you though because the negative side of the dome lights gets ground directly from the BCM....I assume the BCM uses Pulse Width Modulation (PWM) to decrease the amount of "ground" going to the dome lights to dim the lights before turning them off completely.

So you could try connecting your hood light directly across the dome lights...assuming fuse 34 and the BCM can handle the extra current then the hood light should also dim then go out in time with the dome lights.

To be on the safe side you should connect a relay across the dome lights to seperately power the hood lights....the relay will drop out once the ground supply gets too low.

 

[teckman02]

if you want it to look OEM you can do this

Jeep Grand Cherokee WJ - under hood lamp

 

[TwoBobsKJ]

I'd think with an LED replacement bulb there wouldn't be a concern with excessive current draw, would there?

Thanks for the link, Teckman!

Bob

 

[4x4kayak2112]

I'd think with an LED replacement bulb there wouldn't be a concern with excessive current draw, would there?

Thanks for the link, Teckman!

Bob

I wouldn't think so.

Sent from my Home Phone using Tapatalk

 

[jeeptorino68]

if you want it to look OEM you can do this

Jeep Grand Cherokee WJ - under hood lamp

that is exactly what i am doing
write up to follow once i figure how i want to wire it.

 

[teckman02]

that is exactly what i am doing
write up to follow once i figure how i want to wire it.

i would just wire it to the batt it is a just a roller swich or something i have one just need to get it put on

 

[jeeptorino68]

yea i might
i was hoping for the 8 minute timer feature if i can figure it out...

 

[Jo6pak]

Here is my under hood light.:happy3:

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[/URL]

 

[TwoBobsKJ]

Here is my under hood light.:happy3:

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[/URL]

:happy175::happy175::happy175:

 

[yellocoyote]

Mine looks like that too - just in a different location.

 

[Billwill]

yea i might
i was hoping for the 8 minute timer feature if i can figure it out...

Wire it directly across the dome lights as I have suggested....either directly or place a relay over the dome lights and have that relay power your under hood light.

You can find the 2002 KJ Service Manual....including circuit diagrams...here:

Index of /manuals/Jeep/KJ

 

[TwoBobsKJ]

Wire it directly across the dome lights as I have suggested....either directly or place a relay over the dome lights and have that relay power your under hood light.

You can find the 2002 KJ Service Manual....including circuit diagrams...here:

Index of /manuals/Jeep/KJ

Hey BillWill, I'm a mechanical guy and not an electrical guy. When you say wire the under-hood light "across the dome lights" what do you mean exactly? And I'm not being a smart aleck either - I'm ignorant about most things electrical and would like to understand what it means. :worship:

Thanks!

Bob

 

[Billwill]

Hey BillWill, I'm a mechanical guy and not an electrical guy. When you say wire the under-hood light "across the dome lights" what do you mean exactly? And I'm not being a smart aleck either - I'm ignorant about most things electrical and would like to understand what it means. :worship:

Thanks!

Bob

No problem.....what you need to do is effectively run a pair of wires into the cabin and connect a wire to each side of one of your cluster bulbs so whatever voltage the cluster bulb gets your hood lamp gets.

This is not really feasable so what you do is connect one wire directly onto fuse 34 in the inside fuse panel. You need to splice your wire onto the Pink wire coming off the bottom of fuse 34 so that it uses fused current. You will find pink wires on connector C1 pin 15 and C1 pin 12 and maybe C2 pin 18...either will do.

The other wire you need to connect to the yellow wire on C1 pin 23 or pin 24 or maybe C2 pin 30...either will do. One of these wires you interrupt with whatever on/off switch you are using to switch your hood lamp on while the other lead goes to the other side of the lamp.

If you are using LEDs in your hood lamp I believe the current draw should not be too bad.....leave fuse 34 as it is at 15 A....if the fuse does not blow and everything works fine then leave it all connected as stated.

If the fuse 34 blows or you find that the dimming function of the Dome lights no longer works then have those two wires that you have spliced in go straight onto the energizing coil of a seperrate relay rather. This will mean that the relay...which draws next to nothing current wise...will energize as long as the Dome lights are ON.
Now you put one side of your hood light straight to ground and the other side to the "Normally Open" contact of the relay. The other side "Common" of the relay contact goes via an inline fuse directly to positive on your battery...via your desired hood on/off switch.

So now when the Dome lights are On, the relay is energized and supplies current seperrately to the hood lamp. As the Dome lights get about half-dim, the relay will power off.:icon_cool:

 

[TwoBobsKJ]

Bill that's awesome - thanks for the education! :happy107:

Bob

 

[jeeptorino68]

thank you both for all the info.

 

[Luke]

^^^ What he said