My truck has been starting pretty hard the last week, and the weather here in California has been better than decent.

Today, the truck wouldn't start and I quit trying after the 5th cycle. Batteries are sitting @ 12.5 V, grids are only dropping about 10.7 V when you turn the key on. I Pulled apart the intake to look into the grid heater.

To the question, these should be getting red hot? Mine get luke warm if you hold your hand about 1/2" above them. Just want to verify this since I have never had to change it before.

Thanks for your help.

and the truck is a 2004 5.9l

 

test each battery individually (remove cables from them so you are not getting juice from the other battery). a single battery that is sub par can cause a lot of strange things such as what you are experiencing. if you have 1 battery that is subject, then replace both as a pair. never just replace 1 battery on a dual battery set up.

 

forgot--- load test the batteries. just doing a meter is only going to show voltage. a dead battery can show 12 volts but when load tested go to darn near zero

 

Yeah, and your truck should start easily below freezing... the grid heater only comes on below ~55*.

 

Ok, so it was below 55 this morning. That would make sense why it starts fine in the afternoon and has been a bear to start in the morning. It was above 55 when I tested this again, they still kicked on.

Update to the tests. Each individual battery is showing 12.8V by themselves. I realize a load test may show different results, to the contrary, you can crank the motor all day long (did 5 cycles this morning for about 10-15 seconds each) and there is no draw down noticeable by the way the starter is acting.

Pulled the wiring off the grid heater and tested it, 12.6 V is making it to the heater. Place the wiring back on and both are only getting 10.7 ish.

scrubbed the positive and ground terminals on the heater and manifold to make sure I don't have an issue there either (though I'm pretty sure it grounds with the 4 bolts through the manifold as well)

Anybody heard of both heaters failing at the same time? From what I searched before I posted, it didn't seem common.

And I appreciate everyone's help.

 

i have also seen people add another ground to the heater.

 

Man, I'm having a hard time with the fact that your truck won't start at 55* with out heaters... have you checked the codes? You may have a bad injector, rail pressure sensor, rail pressure relief valve, FCA, fuel pump... something is just not right with this picture...

 

no codes showing up. Only has this issue on cold mornings the last couple weeks. Haven't had any issues with starting it once its warmed up, or in the afternoon when it has been mid 60"s plus.

 

Do you have a block heater cord installed? Plug it in for the night and see how it fires in the morning.

I'm with madhat, there has to be more going on than that. There are guys doing -10 cold starts without grid heaters. Sure its rough, but it fires none the less. I seriously doubt your cummins is THAT cold natured... powerstroke maybe, but these trucks are stout.

 

mine does same thing heater light stays on for bout 3 seconds at 55 degrees and starts but runs rough and white smoke its all stock except a predator programmer does it on all settings and then after that never has the same problem till the following morning but sometimes the heater light stays on for around 15 or 20 seconds and starts perfect any ideas on that ive narrowed down its something to do with the heater?