a weird one

[jwalterus]

I have a weird one for you, whoever can figure this PITA out can have.....

The knowledge that they are smarter than the techs at all the local shops that work on Dodges.

Here's the situation:
Co-worker's truck.
'05-ish (it's 03, 05, or 08 , I can't remember)
1500, 4wd, auto, 5.7, something like 150k miles
unmolested truck, it's strictly a driver for him

I'll try to explain what happens....

Randomly when starting on a cold engine, it will start cranking, and before it actually starts the engine, it will stop rolling over dead in it's tracks. Sounds like it rolls about 1 revolution when it happens.
When it does this, the horn give 3 short honks.
On a warm engine, it will not do this, the colder it is, the more times it will do it in a row, to the point that around 0°F it will drain the battery down to nothing from short cranks without starting.
In 40°F about half the time, it will do this once, then start normally.
At 60°F or above it will start normally more often than not.

Local shops tried checking continuity on all of the wiring, couldn't find anything wrong.
They tried the shotgun swaptronics approach, didn't fix it.


Any thoughts?

 

[79jasper]

Clean all the connections.
The security/alarm system is trying to engage.

Sent from my SM-G892A using Tapatalk

 

[snicklas]

Does it have the Gray Anti-Theft key? If so, does the red light on the dash stay on? I agree it sounds like a security system issue...

I had an 02 Neon, and if you put in a non security key, the red light would stay on and it would shut the engine down......

 

[hce]

I would look at all grounds, then battery, cables and starter. Check the starter brushes. I'm just pondering if the voltage when cold cranking is getting pulled so low it is messing with the security system. Also follows the rule of check the easy stuff first even if it does not seem like the problem.

 

[Pork_Chop50]

Even though it's gasoline, could the issue be cold temperature and fuel starvation? The alcohol has a higher "freeze" point, or at least where it starts to gel. And if there is any water build-up from the ethanol fuel attracting it then the cold temps could cause the higher pressure fuel system to really struggle to push ice through it. The anti-theft system could be warning of a fuel issue... but then I'm just playing devil's advocate. I know so little about the newer vehicle systems it's astounding.