My 2004 F-150 has to be boosted off in order for it to start, leaving me to believe that the battery was the problem. I noticed that it started as soon as the cables was connected and switch turned on. The vehicle runs just fine, but when you stop it the vehicle won't start unless it is boosted off again. I thought it was the Alternator since it seemed that I was running off of the power from the battery. A rebuilt alternator was installed and it is doing the same thing.

The headlights and park lights will come on by itself after sitting with the cables connected for awhile, and a clicking noise comes from behind the drivers seat. It has me dumbfounded as what the problem could be now. Can anyone who has had this problem or is a machanic who know about this problem tell me what to look for? I thank you all for any help with this problem. The vehicle only has 34,000 miles on it and the engine is still clean like it was when new.

 

Welcome to fte

You have what could be a tricky problem. For right now, I'd advise you to pull the ground conection from the battery whenever it's going to sit for more than a few minutes. That MIGHT allow you to start it without a boost. If the batery is constantly being run down and recharged, it won't last long.

To solve your problem, you need to establish a few basics. You need to find out what the battery voltage is after you shut it down, and how it changes when the truck is running.

Ideally, it should be 12.65 v when its shut down, and something like 13.8 when it's running.

If it's low right after you shut it down, pull the ground off the battery and check the volts right on the battery. If it goes up when you do that, you have a significant current drain. (This is what I think is at the hert of your problem. )

If it's low with the engine running, then for some reason the alternator isn't charging. A lot of auto parts stores will test it for free if you pull it and take it in.

If those tests don't show anything, you could still have a current drain. Finding it gets a little complicated because electrical systems these days don't immediately 'go to sleep' when the engine is off.

What you want to do is measure the current after things are shut down for a half hour or so.
To do that
1. Disconnect your ground cable from the battery
2. connect the cable and the battery with a short jumper wire
3. Also connect a current meter between the battery and the ground cable
(black(minus) end to battery and red(plus) end to ground cable)
4. Set it for a fairly low current range -- say 500 ma
5. Disconnect the wire from the battery to the ground cable -- being careful to not disturb the connections to the current meter.

You should read no more than 100- 150 ma If there's more, you have a current drain.

Usually the way to find the drain is to pull fuses one at a time to see when it goes away. WARNING -- somehow disable your dome light (pull the bulb?) and any other light that comes on when the door is open. If you don't and you open the door, it will blow the fuse/breaker in your currrent meter. (Some have resettable breakers).

From your post, I gather that you probably don't have a meter, and you probably don't know how to use one, but it's really hard otherwise.

So, find a buddy, or do some research at the library.

If you eliminate current drains as your cause, and your batt and alt are good, you could indeed have a tough problem.

Good Luck,

hj