Hi. Since I have survived my latest medical crisis, I thought I should fix my truck while I can. (01 F350 diesel) It has been sitting for about six months. The batteries keep going dead. Unfortunately it has two alternators. There must be a short somewhere. At one time I knew how to hook up the meter between the battery and the cable to show a current draw while it was off. But it has been so long since I did it that I forgot how to hook it up, and what to set the meter on. Plus how would it work with two batteries? Disconnect both??? Can anybody help with that?

Also is there a way to not use one of the alternators? I don't need the extra power. Can I tape off the wires and get another belt for just one alternator. The sticker on the truck shows both ways.

Thanks for any help.

 

disconnect Both Battery Negative leads and now you can connect multimeter set to the High Amprage scale.. also select the Ports on the meter for AMP testing....
connect the Red Lead to either Battery Negative Post then connect the Black lead to Vehicle Ground (this can also be either of the disconnected Negative battery cables and your meter will show Current Draw.

 

Thanks for the reply. If all is good, will it say zero?

 

no you have a Draw from the Radio keep alive and the Engine/Transmission Computer and any other items that always have "Keep Alive" power to them but it should not be an excessive draw like 5 Amps would be....... I'm not sure the exact Parasitic current draw for your truck but with Key Off and all doors closed and engine Hood Light out you shouldn't see more than 25 to 50 Miliamps IMHO

 

I keep a Battery Minder on my truck when it is not in use as batteries will go pretty Low in 1 month.


EDIT: also any Anti Theft system will also draw Current.....

 

I will give it a try tomorrow. Thanks.

Do you happen to know anything about two alternators, changing to one?

 

Good idea. I have one I used to use on my motorcycle. I will start to use it.

 

I had the Dual Alternator on my 93 IDI F250 I just swapped the bracket from the dual to a single Alternator bracket and change the belt to a smaller length.

I just taped up the connectors for the lower alternator so that I can go back to dual IF I ever have the need.

my batteries were not split as in an Aux system so I didn't need to do anything for Battery Cabling.

 

I have one down at the bottom and one near the top. I should be able to just use the top one. I was going to try it but didn't know if it would work. I have a belt for the single alternator already. My alternators are original, so that doesn't help my battery problem either. Great news. Thanks.

 

Hello, I wish I could help but Im in need of assistance or counseling aswell. I left the lights on with the motor off and when I went to turn the F/150 2003 xlt obviously didnt start,but at first. I waited for a few minutes to get the battery at is normativity and it turned on. Sadly the next day it took three clicks over switch to get it started. yesterday it took 8 turn on clicks to start and now it only clicks and makes a thumping noise infront of the hood on driver side. I took it to autozone to test battery and is in good condition. I tryied the basics but it just wont start. Lights come on brights but it wont start. Maybe I might get lucky with a response or should I just burn the demn thing... Thanks.

 

Get another person. Turn the headlights on, and leave them on when you try to crank it over. When you try to crank it over, do the lights go out or almost completely out? If they do, your battery is no good, one of the cable connections is no good, or one of the large cables, either the ground or the + is no good.

 

Unfortune for me the lights dont even blink they stay good. Except the cabin ones do go out but come back again.

 

That is a clue. Apparently you have a connection problem downstream on that cab circuit only. You are going to have to do some troubleshooting. You need a testlight.

Find the starter relay. I think it's mounted on the firewall on the pass side, not sure. But it will have the large battery cables going to it. There should be smaller (but still fat) wire coming off the starter relay going to the underhood fuse box.

What I would do is pull the cover off the underhood fuse box, and look it over good for any corrosion or melting. I would then pick some of the large fuses, clip your testlight to a good ground and then probe one of these fuses. While holding the testlight on to the fuse, get someone to try and start the truck. If the testlight goes out, you are downstream of the problem. If it stays bright you are upstream of the problem.

 

Good day, finally I had the chance late last night apply another method since mecanic tested battery and it was low. He suggested to charge it so I said to check fuses but denied because the problem is the battery. But I didnt charged it since fuses where not checked I was remineded on your guide. Late night my neighboor next door helped by putting another battery pretty much same voltage and it still did the click. So now I know is not the battery but this time we tried it manually. Wire from starter which is underneath the chasis to the positve on battery of course had the switch in on position and did the same clicking. So we think is carbs. Hopefully today after some paragraphs will take it to get it fix. But my question is if theirs nothing wrong with it what is next...!!! Fuses, alternator, solenoid.....or maybe is just the battery needed but with more power after all.

 

You have a 2003 and it has carburetors on it? Boy I am confused now.