Toggle Switch For MM3

[Opie15]

Hello all, got a question I've noticed during the cold weather when my truck does its preheat cycle before starting the voltage on MM3 tunnel is dropping to around10.5 volts it starts at around 11-12 volts but drops quickly.

Sometimes get black display and flashing red and green light on MM3, occasionally it will go out during starting and flash red light once and boot up on its own.

Normally I have to unplug OBD shut the truck off and restart and plug back up.

I've had this issue once before and it was the batteries.

Replaced them both less than 2 years ago.

So I load tested them today they seem to be ok.

(Each one separately with everything disconnected) so I was just curious if anyone had ever thought of wiring it to a toggle switch and cutting it on after the truck is running (the monitor) that.

I would assume it would connect in-line to one of the wires going to the OBD plug.

Any feedback or suggestions would be appreciated.

Thanks

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

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[watersupply189]

Hello all, got a question I've noticed during the cold weather when my truck does its preheat cycle before starting the voltage on MM3 tunnel is dropping to around10.5 volts it starts at around 11-12 volts but drops quickly.

Sometimes get black display and flashing red and green light on MM3, occasionally it will go out during starting and flash red light once and boot up on its own.

Normally I have to unplug OBD shut the truck off and restart and plug back up.

I've had this issue once before and it was the batteries.

Replaced them both less than 2 years ago.

So I load tested them today they seem to be ok.

(Each one separately with everything disconnected) so I was just curious if anyone had ever thought of wiring it to a toggle switch and cutting it on after the truck is running (the monitor) that.

I would assume it would connect in-line to one of the wires going to the OBD plug.

Any feedback or suggestions would be appreciated.

Thanks

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

Sounds like your grid heater is pulling the juice down and that will cause your display to do that.

You said your batteries seem okay after load testing.

What did the load test show?

Even though you just replaced them two years ago you still could have one weaker than the other.


2016 Ram 3500 CC 4x4, G56, Dr. DRD medically cured!

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[Opie15]

They were at 10.8-11 (analog meter, not digital)volts after 10 second load but wouldn't drop below 10.5 I would say.

They both tested the same. I have one of my PIDS on MM3 set up to OBD voltage and that's about what its saying too.

Just thought it would be nice to be able to power off and on when you want.

Been tossing around installing a Gauges pod and only using it to change tunes which I never do...LOL.

last time this happened one of the batteries would drop to about 8 volts under load.

Truck seems to crank good haven't had any issue with that yet.

Batteries have a 3 year replacement warranty so I was hoping it was the batteries...LOL while still warranted.

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

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[Opie15]

Granted the 10.8to 11 volts does say weak under load it doesn't show bad.

The photo is with meter unhooked by the way just using as a reference to what I'm saying.



2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

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[watersupply189]

Granted the 10.8to 11 volts does say weak under load it doesn't show bad. Photo is with meter unhooked by the way just using as reference to what I'm sayinghttps://uploads.tapatalk-cdn.com/202...fb820917f1.jpg

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

Try throwing them on a battery charger overnight and see what the load test does then.

10.8-11 is is weak for these trucks and will definitely cause your MM to do what you describe.

Mine was that low and it did the same thing until I replaced both of them.

If your batteries are under warranty then I would trade them out.


2016 Ram 3500 CC 4x4, G56, Dr. DRD medically cured!

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[AK Bob]

Hello all, got a question I've noticed during the cold weather when my truck does its preheat cycle before starting the voltage on MM3 tunnel is dropping to around10.5 volts it starts at around 11-12 volts but drops quickly.

Sometimes get black display and flashing red and green light on MM3, occasionally it will go out during starting and flash red light once and boot up on its own.

Normally I have to unplug OBD shut the truck off and restart and plug back up.

I've had this issue once before and it was the batteries.

Replaced them both less than 2 years ago.

So I load tested them today they seem to be ok.

(Each one separately with everything disconnected) so I was just curious if anyone had ever thought of wiring it to a toggle switch and cutting it on after the truck is running (the monitor) that.

I would assume it would connect in-line to one of the wires going to the OBD plug.

Any feedback or suggestions would be appreciated.

Thanks

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

I believe you have a combination of weak batteries, cold temperatures and low state of charge.

To combat this I would recommend charging your batteries overnight with a trickle charger during the cold spell.


2014 RAM 3500 (Aisin) 3.73 4X4 Limited Crew Cab Long Bed DRW. Oil Bypass Filter, Fuel Filtration Kit and 50 Gallon auxiliary fuel tank.

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[Opie15]

I believe you have a combination of weak batteries, cold temperatures and low state of charge.

To combat this I would recommend charging your batteries overnight with a trickle charger during the cold spell.


2014 RAM 3500 (Aisin) 3.73 4X4 Limited Crew Cab Long Bed DRW. Oil Bypass Filter, Fuel Filtration Kit and 50 Gallon auxiliary fuel tank.

Sent from my iPad using Tapatalk

Ok guys will give that a try.

Thanks for the info I will check with Sam's as well about doing a exchange on them.

Problem is by the time I drive up there they will have a good charge on them may have to use the wifes ride.

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

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[Opie15]

I believe you have a combination of weak batteries, cold temperatures and low state of charge.

To combat this I would recommend charging your batteries overnight with a trickle charger during the cold spell.


2014 RAM 3500 (Aisin) 3.73 4X4 Limited Crew Cab Long Bed DRW. Oil Bypass Filter, Fuel Filtration Kit and 50 Gallon auxiliary fuel tank.

Sent from my iPad using Tapatalk

Is it ok to hook trickle charger to one battery ( with them connected in truck) won't it charger them both at the same time?

I only have one charger reason I ask

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

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[watersupply189]

It’s best to trickle separately. you could do both but will take forever to charge.


2016 Ram 3500 CC 4x4, G56

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[AK Bob]

Is it ok to hook trickle charger to one battery ( with them connected in truck) won't it charger them both at the same time?

I only have one charger reason I ask

2015 cummins 2500 crew cab w/ rf 68 s&b cold air,mbrp stainless 4" w/ muffler,mm3 tuner from double r diesel,xdr throttle valve delete,xdr egr delete,shibby plug kit, traxda 3.5"/2" lift, 20x12 hostile wheels w/35" amp at/g tires

Yes you can use one charger to charge both batteries as they are connected in parallel.

However as our friend @watersupply189 stated above keep in mind it will take twice as long.

The only way to increase the desired charge time is to use a higher amperage charger.

I would recommend a minimum of 5 amps to a maximum of 10 amps for overnight charging of both batteries.


2014 RAM 3500 (Aisin) 3.73 4X4 Limited Crew Cab Long Bed DRW. Oil Bypass Filter, Fuel Filtration Kit and 50 Gallon auxiliary fuel tank.

Sent from my iPad using Tapatalk

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