Hey guys im not a ford guy but I borrowed one and it broke

So long story short I borrowed my inlaws beat up old f250 (2001 7.3) and I blew a brake line on the way home. So I replaced the brake line and since I can't leave well enough alone I started trying to trace a parasitic drane that has been going on for a while. Without any wiring diagrams or working knowledge of the truck I am stuck.

I got so far as to determine I have a 350 ma draw. Pulling the fuse for the multifunction switch drops a 130 ma and pulling the 5amp fuse for the pcm/abs/brake lamps drops it like 200 or so. So anyway. Can anybody tell me what normal reading would be? Also any advice on tracing the drain? This is my first time looking for a parasitic drain and my only working plan is disconnecting stuff on those circuits.

 

remember...

computer memory is ON,
Radio memory is ON.
if it has key Fob remote for doors.. its ON.
alarm system is On.. even if OFF..
and there is NO short-cut.. measure, disconnect, measure, disconnect, measure.. etc.

best of luck

 

 

If you have a weak battery it will make the problem bigger. The computer goes to sleep after a hour or so after you let the truck cit. As soon as you open the door it wakes up. Now I have a 07 GT500 and if i let it sit for 2 weeks it will kill the battery. I have a battery tender so that doesn't happen. So check the battery first. If the truck sits than get a tender. Problem solved.

 

Hit the lock button twice on the key fob. That shuts down most computers/ puts them into a sleep mode. Should be fine doing it with the hood up.

If there is an underhood light I would disconnect it or pull the bulb while testing.

On road service calls my company considers anything under 0.80 A draw to be a passing number (obviously its a general number as we deal with every make and model). Better rule of thumb for reliable results from a battery is "for every 100 cold crank amps that the battery is rated for allow 0.10 A of draw. " This gives a bit of safety in knowing the battery will still start the engine after sitting for normal periods of time.

The Bone makes a great point about a battery tender if the batteries are older and/or if the truck isn't used regularly. Regular use would be driving multiple times per week and trips more than 30 minutes.

Questions. How old are the batteries? Do the batteries dates match? 3 to 5 years is the expected life in your neck of the woods. If they have been discharged often, damage to the batteries will occur. Two dissimilar batteries will weaken each other over time.

To answer your question about normal reading on that truck, Not sure if it helps or not but I think my last test on my truck turned up a 0.36 A draw. I have a 2005 F250 with the 5.4

-Kevin

 

It's your mother in law...

Well, someone had to say it.


But seriously, does this one have cruise control? I think (not positive) that '01 was in the batch of recalls for CC modules being "hot" all the time? Led to a few fires iirc? If this one has the CC module, has it been in for the recall work?