Ford 7.3 Diesel Dead Batteries

[Brian Castille]

In January I drove to lunch like normal and when I went to leave the office the truck was dead. I put a multimeter on it and batteries were less than 1 volt. I got new batteries and the truck fired right up no problem. Yesterday, I drove the truck around like normal and no issues. Today, I go to leave and there is no power. I open the truck and multimeter reading is 0.26 volts. Not sure how it is going from running fine to basically dead. Any thoughts?

[hurricane matt]

Test alt.
Check ground straps
Any auxillary stuff on it?


I just replaced Batts on my Duramax, lasted 2 years.



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[dk2429]

There's something shorting out and killing those batteries.. Could be a list of things.

[Brian Castille]

Thanks. Alternator is good, nothing is on and I was thinking of grounds but you would think that it would show right back up after it happened the first time and not wait so long. I'll go see what I can find in there....

[boom!]

Check the glow plug relay. That’s a pretty good amp draw to kill 2-800amp batteries that quick.

[bwguardian]

^^^...This, easy to do as it's basically a starter solenoid.

[hurricane matt]

Glow plug relay as in it's stuck on is that what you are suggesting? Can he just pull it for the time being or will truck not start with it removed?

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[bwguardian]

Originally Posted by hurricane matt

Glow plug relay as in it's stuck on is that what you are suggesting? Can he just pull it for the time being or will truck not start with it removed?

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Yes, putting a light power indicator or volt meter on the engine side after the truck is running for a couple of minutes would be the tell tale. There are two solenoids there on the passenger side of the engine adjacent to the fuel filter bowl. One is the glow plug solenoid...the one nearest the firewall...and the other is for the air heater... the one nearest the radiator. If need be, the one for the air heater can be utilized for the glow plug to get it started if cold in a pinch...

Brian Castille, what year model and make is your truck. I assumed you were not talking about an Excursion as these have glow plug modules like came on the later 6.0L Powerstrokes...unless it is a California F-series truck, which would also be equipped with the glow plug module...

[Brian Castille]

Originally Posted by bwguardian

Yes, putting a light power indicator or volt meter on the engine side after the truck is running for a couple of minutes would be the tell tale. There are two solenoids there on the passenger side of the engine adjacent to the fuel filter bowl. One is the glow plug solenoid...the one nearest the firewall...and the other is for the air heater... the one nearest the radiator. If need be, the one for the air heater can be utilized for the glow plug to get it started if cold in a pinch...

Brian Castille, what year model and make is your truck. I assumed you were not talking about an Excursion as these have glow plug modules like came on the later 6.0L Powerstrokes...unless it is a California F-series truck, which would also be equipped with the glow plug module...

Thanks. It's a 2002 F-250 ordered and purchased from a Clear Lake area dealer.