Battery problems after relay safety recall repair

[Brutal_HO]

The Cummins doesn't need the intake air heat to start unless it's below -20 or so.

Bypass saves the battery supply and could help prevent the truck from going into battery saver mode, more likely to occur on trucks without dual alternators.

The grid heater is going to cycle anyway once started.

 

[Blythkd1]

To the OP, if you live in Tampa you never need to wait for the grid heater. Just hold the brake and tap the start button twice. The grid heater just causes unnecessary drain on your batteries for no reason.

 

[AH64ID]

just out of curiosity, why do you bypass the intake air heat up when its cold out - also did it start hard when you do that and its below 20F out?

Cummins advertises the ISB as not needing any starting aid above 10°F, but the programming is there to use it with an intake temp of 66°F and below. A lot of the warm weather use is for emissions, but that’s really more of a post-heat cycle thing than a pre-heat thing.

I started my 05 one winter without a grid heater when it was -25°F with weak batteries. It started, but wasn’t happy. I modified the programming of the grid heater and shut it off completely above 32°F, and didn’t have it on very long at all until 10°F.

My 22 has been started in -18°F and I didn’t wait for the full WTS timing and it had no issues firing.

 

[Nick]

I'm going to get one no matter what. At this point I feel like it's a basic tool I should have.

You need your foot on the brake as already mentioned and two quick pushes on the start button to prevent it from going to heat cycle .