hello all, odd problem with the truck today. i put a battery tender lead on my battery today and now it wont start. it turns over and the battery sounds strong. i dont hear the fuel pump run when i first turn the key anymore. i think it used to whine for a few seconds first anyway. still a new truck to me. relay in 66 slot was corroded a bit so i put a new relay in but still nothing. does some other weird things now too. when its in park the rear camera in mirror will flicker as im trying to start it. no passlock flashing light on dash. sometimes it will try to run for just a half second then die. other times nothing. i pressed the schrader valve on the fuel line and some fuel came out but not under pressure. could it be fuel pump?

 

Ok strange addition. With key in turned on or completely out, when I step on the brake, the radio turns on and the green flasher arrows light up...

 

Why the battery tender? Are you sure it is properly connected? Have you tested the output voltage and amperage of the battery? Do you have a sunroof? Has it been raining lately? Did you clean out the sunroof drains when you took possession of the T?

If so, it sounds like you have a soaked BCM from water intruding upon the BCM harness (passenger side foot well). Remove the passenger side foot well ans inspect for water on ANY of the BCM connections. Some have tried drying the BCM, but it was never the same. New BCM is the fix most of the time. Oh, it has to be programmed by a TECHII.

I hope it's just a very low battery. Easy and relatively cheap fix. Buy an AGM battery if you are not going to use it for periods of time.

 

I put the tender lead on as it doesn't get driven that much now that I'm so busy at work in my work truck. It hasn't been wet. It's been in my garage. And it was fine before I unhooked the battery to put the leads on. I'm gonna take the battery out and test I think. Still sounds plenty strong when attempting to start. Also thinking maybe the fuse panel? The relay was green and partially eaten away. Thinking it could be corroded inside?

 

replaced what looked like the original battery with a red top. old one was bulging a bit. no change though so i had it towed to the dealer. apparently the fuel pump control module over the spare tire was to blame. they found a chafed wire too but that wasnt the issue. im just hoping this is all the surprises this truck has in store for me as that took my rocky road slider money to fix.