1988 F-350 with a 6.9 When I'm idling the volt meter sits from 8 to 10, in the mornings when the truck is cold it sits at 8 until I get moving down the road then it gets up to 12 where it belongs. But the thing is, is that when I turn anything on like the heater fan, the needle dives down to 8 or less. I know my batteries are shot, because if it doesn't start on the first try, then there's no starting it, the batteries are dead. Would old ***** out batteries be the cause of the low voltage? I would think that once it's running the alternator should be strong enough to charge the old batteries, and run what ever I have turned on. I just don't feel like running out and spending $200 for new batteries and then turning around and buying a new alternator too, but it looks like that may be the case. What does anyone else think?
I would say take the batterys out check to see if they need any fluid then get them charged and tested at ur local parts store if they come up good then move on to the alt and im sure they can test that too... i know it involves a bit of work but atleast you will only be replacing what u actually need.
your alt.should be charging at 14.6 volts even if your batts. are shot. do you have a multimeter to see what the alt. is actually putting out?
__________________
94 ford f250 7.3 turbo idi headlight mod,electric fuel pump,tinted windows all around,straight piped and 6" stack and sweet camo trim in the cab
I'm not going to be able to dig into this until the weekend, but one thing that I was thinking about on the way home tonight is, the dimmer switch for the headlights on the floor is stuck on high. It doesn't bug anybody because the lights are dim enough on high beam. So if it is the alternator and I replace it, I'll probably have to replace the dimmer switch too because my lights will be to bright.
The batteries are old, I've kept them clean and have grease on the terminals, water is good, I just think that it's their time to go.
well,you kinda know what needs to be done first then.
old batteries are hard on that expensive starter,just keep this in mind.
im sure your looking for help to push ya into spending that $200 cus you know you have too lol.but letting your starter drag slow is bad,bad news.this should help ya feel better lol.
always replace what is known to be bad first and go from there.
you then want to be sure your alt is charging,so test it or have it tested.you dont want to cut your new bats life span short right out of the gate.
dont just buy an alt if you notice your new bats are not charging.it could be your voltage regulator/wires/cables.this is why its important to test things first and put your $ into the correct part(s).-old batteries of course is a given lol.some people just replace them after 2 yrs no matter what(i think thats a bit drastic)but helps to show how some keep up on batteries.
__________________
1993 F250 Heavy Duty 4x4 XLT, regular cab, two tone with red interior, 444CID/IDI/NA International Diesel, E40D auto, 1356 BW manual shift TC, Dana 50 TTB front/Ford-Sterling 10.25 2nd-gen full floater rear with 3.55:1 gears.That's stock.See my garage for mods. 47k original miles. Carfax clean w/last OR 29,200 in '06. Not yet on the road. Brand-new to me.
♠ Real Trucks Don't Have Spark Plugs.♠
If you have shorted cells in the battery, the voltage will show low.
Shorted cells in the battery would keep the alternator charging wide open trying to get the voltage up to 14 volts where it won't go because of the short, so now the alternator dies.
And the the low voltage causes the starter to turn slower, so you have to crank it longer, which will kill the starter.
Most auto parts stores will load test the batteries and the alternator output.
That would be an excellent first step.
Just make sure the batteries are not hooked together when they test them or you may get a false good report.
Unhook the positive cable from on or the battery and you are then good to go.
Your problem could be a bad voltage regulator, bad alternator, a bad battery or two or possibly a bad positive battery cable.
Replacing the entire list would probably cost 600 dollars.
Testing everything and replacing only what is bad, maybe as little as 40 dollars.
But I do know if not fixed soon, you will be able to add another 200 to the list above for a starter.
__________________
86 F250 HD 6.9 IDI ATS turbo "not exactly" stock 4x4 T19 BW1345 3.55LS both ends D60 front, 10.25" Sterling rear, ram air, dual stacks.
Ya, the list just keeps adding up. I'm not driving the truck very often anymore, I have a 70 mile commute so I'm using my little car as long as I can, until the roads get bad. I just wanted everything working properly come winter. Another thing, I'm working 6- 10's so come Sunday when I have time to do anything, I'm so wore out that all I want to do is lay on the couch and watch football, and catch parts of the nascar race. Thanks for the imput, I'll keep everyone posted.
dont forget to clean and grease the terminals when you put the batterys back in! i was having troubles starting and the terms looked good but a cleaning and it started like a champ
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.
