Transistor IRFP 9140 Mosfet for interior lights

[drvahe]

Hello friends, I know how terrible the Bronco's interior lightning is, and this is not the first thread about it. So I got Lights from @IAG Performance , but I didn't like the way how they operated, so by their instructions you need to connect them to the door opening "sensor" wire and if you want you can hook them up to up-fitters. I found a way to make them work in conjunction with OEM lights Since we can't just attach those additional lights to the OEM lights by parallel connection. But we can use OEM lights as a signal to turn on the additional lights in a synchrony way. Initially I was thinking about relaying with a LDR sensor activation, but found an easy and much much less power consumption way by using a Transistor IRFP 9140, this is a P-Channel transistor. I will attach below the simpliest scheme to connect it to the back Dome light.

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[KyTruckPlant]

Nice work! Thanks for sharing.
I assume it was it easier to run to the rear dome?

 

[redone17]

Yeah, what about the front dome light?

 

[KyTruckPlant]

This got me to thinking where the lights should be tied into. The rear dome is good, but if someone in the back seat turns on the dome, wont it light up all four lights?
Maybe tie the rear lights to the rear dome, and the front lights to the front dome?

 

[drvahe]

Nice work! Thanks for sharing.
I assume it was it easier to run to the rear dome?

@redone17
Welcome! Yes it was super easy to route them to the rear dome, so was testing with 4 lights and I didn't like it, front of the car has enough light for me that's why I just used 2 of those IAG lights, but if you want all 4 of course it's better to wire them to the front dome lights so it will work with front OEM dome lights.

 

[KyTruckPlant]

@redone17
Welcome! Yes it was super easy to route them to the rear dome, so was testing with 4 lights and I didn't like it, front of the car has enough light for me that's why I just used 2 of those IAG lights, but if you want all 4 of course it's better to wire them to the front dome lights so it will work with front OEM dome lights.

Using this, I think I will divide my lighting into 3 zones, front off of the front dome, rear off the rear dome, and the cargo area driven by the light in the cargo area.

I owe you a beverage of your choice sir!

 

[skierx728]

I wish I was smart enough to understand how to do this

 

[BroncoRob_Reignited]

Hello friends, I know how terrible the Bronco's interior lightning is, and this is not the first thread about it. So I got Lights from @IAG Performance , but I didn't like the way how they operated, so by their instructions you need to connect them to the door opening "sensor" wire and if you want you can hook them up to up-fitters. I found a way to make them work in conjunction with OEM lights Since we can't just attach those additional lights to the OEM lights by parallel connection. But we can use OEM lights as a signal to turn on the additional lights in a synchrony way. Initially I was thinking about relaying with a LDR sensor activation, but found an easy and much much less power consumption way by using a Transistor IRFP 9140, this is a P-Channel transistor. I will attach below the simpliest scheme to connect it to the back Dome light.

Shout out to Ltjb8 for getting me here and thank you drvahe for this post; it's exactly what I was looking for. I bought the same kit and was very disappointed to find it disconnected from the interior factory light functions. Thanks and Kudos for figuring this out for everyone.

Now to order some electronics! Haven't had this much fun since I dicked around in a RadioShack back in the 90's building my own cable descrambler...

 

[drvahe]

Shout out to Ltjb8 for getting me here and thank you drvahe for this post; it's exactly what I was looking for. I bought the same kit and was very disappointed to find it disconnected from the interior factory light functions. Thanks and Kudos for figuring this out for everyone.

Now to order some electronics! Haven't had this much fun since I dicked around in a RadioShack back in the 90's building my own cable descrambler...

Sure, ask if any questions

 

[CalvinT]

Did you add the bypass diode or is it integral with the 9140 package?

 

[BroncoRob_Reignited]

Did you add the bypass diode or is it integral with the 9140 package?

The diods are the LEDs on his simplified diagram. Where the purple line goes to on the board is where he soldered onto in order to pick up the change in state.

 

[ATLBronco75]

What was wrong with the way the instructions told you to connect it? I have these lights and don’t understand if I should be worried.

 

[CalvinT]

The diods are the LEDs on his simplified diagram. Where the purple line goes to on the board is where he soldered onto in order to pick up the change in state.

There's a diode from the source to the drain. Is that integral to the package or did you add it?

 

[BroncoRob_Reignited]

What was wrong with the way the instructions told you to connect it? I have these lights and don’t understand if I should be worried.

There's nothing wrong with installing per instructions that came with the lights; however, this mod allows you to use your interior light switch to turn the lights on and off rather than needing to open the door or install a secondary switch.

I'm very pleased with the install using this mod as I can turn on all interior lights with the switch above the rearview mirror.

One think to note, I couldn't find an IRFP 1940 transistor, so I substituted another. As long as it's a P-type and within the voltage/amperage range of use, it'll work. I think the transistor I got was rated up to 70V rather than 12V.

 

[BroncoRob_Reignited]

There's a diode from the source to the drain. Is that integral to the package or did you add it?

I can't tell if you're trolling or are confused...

Inside the red box is the transistor. There are no additional diodes... Inside the green box is the rear dome light circuit board. I did make a mistake in my previous post, but it doesn't affect how you connect it. I dont think the diodes on the circuit board are not LEDs, else the symbol would have a couple arrows coming out to indicate light emitting. Those must be the diodes on the circuit board prior to the LED.

Anyway- just connect a lead where the purple line is on the circuit board to the G on the transistor. Yellow wire in harness to S and run D to the new LED lights. Pretty easy tbh.

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