When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
2017 F350. New batteries. New glow plug relay. Cleaned all the connections on the battery end of the cables. Truck will start every single time if we put jumper cables on the passenger side battery and starts with ZERO hesitation. When we put jumper cables on the driver side it won't start. It won't start without a jump. Starting doing this earlier this week. It will turn one time when you turn the key without jumper cables but that is all. Once started it runs all day without issues unless we turn it off for a couple of hours and then it has to be jumper started again. If we leave it for about an hour or less it will start right back up like nothing is wrong.
The first thing I would do is load test those new batteries. There could such a thing that one is bad. At least that would either confirm or eliminate that from the equation.
Start checking your primary power connections too, positives and negatives, be sure to include the starter. I know someone that had a similar issue on his Chevy ant it was a loose power feed to the starter.
Make sure that the batteries are connected correctly, one may have been connected wrong.
Not saying it couldn’t happen, but that would likely fry everything electrical and it would not ever run. That would give him 24V and I don’t think all the electronics would survive.
Sound like the cable that connects the two batteries is broken, corroded or disconnected. Had this happen on my 6.0 once
mine was near the end but a small disturbance in the sheilding can let moister in and eventually corrode it away in the middle somewhere and not all that obvious.
To check disconnect the two pos cables and continuity test end to end
you could pull the "good side" pos off and see if the line has voltage near equal to the "bad side" battery
IIRC the passenger side is where the feed to the truck is, the drivers side is jumped over to the passenger side. If you have a multimeter, you can check voltages by disconnecting each cable on the drivers battery, first ground, check between cable ends for battery voltage, and that will tell you if the cables are bad, should read at or within .2 volts of the passenger battery. This is for the jumping issue. Your main issue is you have weak batteries, one has a cell that went bad which is affecting the other battery. After driving a while the battery will take on a full charge, but will eventually drain that cell when shut down since there is still a parasitic load on the batteries. Your best bet is just replace both batteries and check the cables are good to both.
2017 F350. New batteries. New glow plug relay. Cleaned all the connections on the battery end of the cables. Truck will start every single time if we put jumper cables on the passenger side battery and starts with ZERO hesitation. When we put jumper cables on the driver side it won't start. It won't start without a jump. Starting doing this earlier this week. It will turn one time when you turn the key without jumper cables but that is all. Once started it runs all day without issues unless we turn it off for a couple of hours and then it has to be jumper started again. If we leave it for about an hour or less it will start right back up like nothing is wrong.
Any ideas of how to figure this one out?
This is why I would load test the batteries, especially the one on the side needing the jump!