Roadmaster Remote BATTERY Disconnect - 3.0L Duramax

[five_er]

I know the Roadmaster Remote BATTERY disconnect has a note on it that it's not to be used on diesel engines however I'm wondering if any of you are using it on the 3.0L Duramax and if it is indeed working for you? I bought it before I realized it had this note and have not installed it yet.. It seems like it's begging to be put on..

I've recently setup my Sierra 1500 with a baby Duramax, installed Roadmaster Base plates, Universal wiring harness and Demco Air Force One braking system and this is the last piece I need to figure out as the battery needs to be disconnected on that truck to flat tow.

[rjstractor]

Thank you for sharing your experience. It sounds like you now know why this device is not designed for use with diesel engines.

[five_er]

Well, it's been about a year and as promised I am back to report the status. I've had a number of issues that may or may not be related to the solenoid Roadmaster Remote Battery Disconnect.

In the cold weather (REALLY cold -35) there were instances where my truck would throw error messages upon starting and go into limp mode where I would be forced to shut it off, disconnect the battery and then reconnect the battery (using the switch).. it would then run normal.

I found on a couple of occasions the autostop would engage but when you took your foot off the brake the truck wouldn't start. Forcing me to put it in park, turning it off and back on, very dangerous in my opinion. I've since installed an autostop eliminator as the feature in this truck doesn't work well, at times shutting the engine off before you're at a complete stop (This happened before the device was installed).

I recently had the engine light come on and the following day found the battery dead.

I've disconnected the battery disconnect switch and will see if things improve. I suspect they will. If they don't I will report back.

[Grit_dog]

Jframpey wrote:
I would guess the method of braking assist is the reason for the exclusion. All gas engine vehicles use a vacuum boost to reduce the braking effort. While towing this vacuum is not available and braking requires more effort, but with more effort the brakes can be applied.
On the popular pickup diesels a hydro boost system is used - the power steering pump supplies hydraulic pressure to the brake master cylinder to aid with brake application. With the engine off the effort to apply the brakes is much greater than vacuum assisted systems.

While what you’re saying used to be mostly true, it’s an over generalization and with newer vehicle models is or could be totally false.
I’ve had gasser engine vehicles with hydroboost and in the last 10 years or so, many are electric boost.

[Jframpey]

I would guess the method of braking assist is the reason for the exclusion. All gas engine vehicles use a vacuum boost to reduce the braking effort. While towing this vacuum is not available and braking requires more effort, but with more effort the brakes can be applied.
On the popular pickup diesels a hydro boost system is used - the power steering pump supplies hydraulic pressure to the brake master cylinder to aid with brake application. With the engine off the effort to apply the brakes is much greater than vacuum assisted systems.

[five_er]

I ended up just giving it a try, gambling the cost of the device should it fail. So far it continues to operate as designed. I suspect the suggestion it won't work on a diesel is because they're talking big diesels and not these smaller ones. Time will tell.. I'll keep you all posted.

[JRscooby]

I have no idea, but would guess there might be a issue with diesel could be the starter often draws more amps than gas.
Also diesel often has more than 1 battery, can it disconnect all?

[Lwiddis]

Must have been a reason for the diesel restriction. A manufacturer wouldn’t decrease his/her possible customers without one.