Pac Brake LED

[RagingCajun]

I've just installed a pac brake on my 3500 (03) and I've installed a LED light to show when my pac was engaged. I put it in series with the switch on my dash, but with the light installed I can't get the brake and light to working together. Could the LED be drawing to much circuit or do I have it hooked up to the wrong wires? This mostly for the wife to know when it is engaged. Does it hurt anything to leave it on all the time?

Thanks Keith

 

[wcjp]

I think you'll need to move the wiring for the LED. The switch is a trigger. Wiring a light in series is basically adding a resistor. Are you trying to activate the light when the compressor is activated or when the PacBrake is slowing the vehicle?

 

[jelag]

The switch on the pacbrake is designed to tell the ECM that you want the brake to come on... . what the circuit is doing is creating a path to ground for the pin in the ECM.....

Under no means should a light or 12v be around this circuit... . a 12v feedback into the ECM could damage it, even with the load of the bulb between them... .

What you can do... is trigger a relay with this circuit if your careful... but I don't suggest it.....

 

[HGreen]

What i did to get a on light on my PacBrake switch was multiple things. First I got a replacement switch at my local auto parts store that had the led light built in. I found one just like the PacBrake switch and just switched them. I then inserted a relay into the circuit so tht the switch would engerize the relay providing the necessary ground to the PCM by the provided wire that you inserted into the plug on the engine. When the switch was on, it provided power to the relay and the led. I beleive that I had to use a 3 conductor cable to the switch because the switch need both a hot and a ground input. The output side provided the 12 volts to the relay.

 

[MoparDave]

The diode in your switch is the culprit, but i'd follow Jelag advice.

 

[Pacbrake]

The system is a ground circuit do not feed power to it or damage will occur. As for using the brake the best thing to do is turn it on and leave it on. Only turn it off when the road conditions are bad.