05 won't start in cold weather w/o block heater

I am having a problem with a 2005 ram 2500 5. 9 when cold (below 40 degrees F) engine refuses to start. If you plug in block heater, engine will start even in the coldest weather. I have checked the intake heater and replaced the unit with a new one. All relays are working.

 

Are you sure you are getting heat at the grid heater? I just had a similar issue and found the relays were working, but was only getting 3 volts at the grid heater. Cleaned all connections from relay to grid heater and started getting 12V. Starts fine now. Be sure to check connections at batteries too.

 

Check your batteries. Low volt will cause this.

 

+1
MGrehlinger:
Are you still running your original batteries? I just replaced mine preemptively.

 

Deja vu

HWTRUCKS.



This sounds so familiar. I have been fighting the EXACT problem for 2 years now. I got input from fellow members. You can check the grid heater. (more than likely not the problem) you can check the batteries, (more than likely not the problem). here is my story. I have an 03 5. 9. Just as you stated when it gets below 40 degrees it won't start if it isn't plugged in. I checked this and checked that. Still no relief. Finally this past summer I had an injector start leaking down on me. It would take 15-25 seconds of cranking to get it started.



I purchased a tool from Cummins. (it helps to work for a Peterbilt Dealer and have direct acces to Cummins) I was able to determine my #1 injector was leaking down and it would have to crank that long to build up enough pressure in the system. I replaced the injector and it started like it did when I bought it. Now I have the same problem again. I have talked to several local guys who have had staring problems. the one guy spent a fortune and finally replaced the injectors to the tune of $6000 including labor.



as far as the batteries..... if the voltage is low it will crank but won't fire since the ECm has a minimum voltage requirement to operate the electronics. Found that out after a tow to the local Dodge dealer. If you put a big charger on the batteries it will start . Shut it off and it won't start again until you put the charger on it. If your batteries are old. it would be beneficial to replace them.



If you have any other questions drop me a message back.

Lowell

 

sorry I got distracted in the middle of my reply. After finding and replacing that bad injector it started no problem when it was cold without being plugged in. One morning it was 5 degrees out and I forgot to plug it in. The truck fired up no problem after only cranking for a second or 2. I only replaced the one injector. I should have bit the bullet and replaced all of them but that is costly to say the least.



Lowell

 

Jrutledge

I live in Tok, Alaska where the winter temps are truely severe. You don't really flinch until -65*F outside. I don't even plug my '05 in until 0*. I have even got it to fire at -40*F without plugging in. I usually cycle the preheat twice before attempting to start it. Good batteries are a must and take apart and clean all battery cables yearly. Good luck.



'05, 2500, jacobs brake, webasto preheat, k&N, 125k miles

 

it does some crazy stuff when you start it up at 0ºF after sitting without being plugged in for a couple a days, but it starts easy