Hi all, I have a 90 e350 ford ambulance with 7.3 diesel. my first ford truck. the truck is out of service and used for work truck. most the lighting and ambulance stuff is gone. does every 7.3 diesel take 2 batteries to start it? or does it just have a second battery for the extra lighting. I need to replace batteries, but with the cost of them and i dont use most the halogen lights still left on the truck, would just one work for me? yes it does have a battery selector, 1 or 2 or both and off. thanks!
mark

 

Most if not all of the diesels I've seen have dual batteries.

 

Diesels need a lot of amps to start. Ford puts in 2 750CCA batteries. So the 1500CCA is used to start an engine which has a LOT of compression.

 

Actaully guys, i hate to prove everyone wrong. I had a good "red top" optima battery, that I thru in the truck today, and only had the battery selector on that selected battery. the red top optima is rated at 910 crank amps. and it fired right up, maybe less than 6 seconds of cranking, as it was last run 3 weeks ago. as I remember last year, i fired the truck up on just one interstate megatron battery rated at 850 cranking amps. so I dont get where you need two batteries, maybe if you let the truck sit and fuel drains outta the fuel system back to the tank and it takes more than 20 seconds to crank, but also , a big battery sucker, is when you energize the glow plug system, as I on my VDO volt and amperage gauges, the volts dip below 10 volts for about 30 seconds using about 4 amperes, then after the wait to start light goes out, the volt returns to 12.7 and amps return to less than 1. So maybe this is true on the very coldest winter day, but no, only one battery is needed. as soon as the truck fires, its drawing about 45-50 amps for about 6 minits to charge the batt back up, as this has a massive alternator. after i warmed it up, i started it multiple times using the single "Red top" optima battery. And the motor has good has the factory compression, as its only got 70k miles on it.

 

I never said you needed dual batteries. I said everyone I've seen has had them. If you live in a warm climate go ahead and run a single battery.

 

Yea duals aren't required if you're in a warm climate. Might want to bag up the other terminals that aren't in use, noticed you said you have a battery selector that's a nice feature.. Those ambulances seem to have everything imaginable,don't they? Lol