1997 Ford F-150 battery drain

JOHN L FOLEY

MEMBER
1997 FORD F-150

Electrical problem
1997 Ford F150 V8 Two Wheel Drive Automatic

my trucks battery will drain & not start.I have taken it to the ford dealer 4 times & their computer cannot find the reason why.
my neighbor took his volt meter & after removing fuse by fuse & checking for any drops in voltage, found that, under the hood, fuse 22 had a 300 ma drop & fuse 6 had a 135 ma drop.
in the cab, there was a 50 ma drop at fuse 20.
when it is dead, the only sound you hear is a relay
clicking from under the hood.
the chilton books & the schematics off the internet are different & they do not show me where the components that use these fuses are located.
i know very little about automobiles so I need your help if at all possible
do not know what would be a good donation for your work on this problem, but i'll give something.
thank you very much
john l foley

6 Replies

SERVICE WRITER

MECHANIC
9,123 POSTS

You are on the right track, let me see what I can find.

What is the total milliamp draw you have? We need to get it around 30 or less.

What liter size engine?

What is the production date on this? Look on the sticker on the door jamb for that.

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Thursday, April 17th, 2008 AT 5:15 AM

JOHN L FOLEY

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2 POSTS

You requested the engine size for the f-150 truck. It is a 5.4 l.
You asked the total ma drop. It is 480 ma total at the 3 fuses I gave you
you asked for the manufactured date it is 07-96

hope this info will help you (and me).

Maybe I better briefly describe the problem again.

The battery drains. By removing fuses under the hood & in the cab, there were 3 fuses that had ma drops.
They were fuses 22 & 6 (under the hood)
and fuse 20 in the cab.

John l foley

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Sunday, April 20th, 2008 AT 10:23 PM

SERVICE WRITER

MECHANIC
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I needed to get the right diagrams..now I need time to look at them.

These are the correct ones:
Junction Box
fuse 20 circuit

Power Distribution Box

Fuse 6

Fuse 22

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Monday, April 21st, 2008 AT 6:02 AM

SERVICE WRITER

MECHANIC
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For the fuse #6, is this an aftermarket radio or original. Does the power to it remain on all the time, even if key is off?

On fuse 22. the power runs to the junction box in the cab from the Power distribution box. I assume that fuse 1 on the junction box was pulled and there was no change on the draw, placing a problem between the two.

I'm suspicious of this particular draw as it involves the GEM module which controls the Battery Saver feature. The draw on this circuit cannot be check for 45 minutes until the timer runs through. This may have been checked too early making it invalid.

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Monday, April 21st, 2008 AT 7:56 AM

GEMINIMECHANIC

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1997 F150 4.6 L Automatic Transmission
Battery draw drain, battery saver circuit, dead battery.
Thought I’d pass some information along that might help someone else with the same problem. Be sure to read the entire post, as it might save you some time.
I recently had an electrical issue with a 1997 F150. This particular truck has a 4.6 V8 with an automatic transmission (although this should apply regardless of the engine or trans.) With the engine shut off, all accessories turned off and key out of the ignition, the vehicle seemed to have a voltage draw which would cause the battery to die after a day or so of sitting without use. The battery was fairly new, so naturally we ruled it out. We performed the typical voltage draw test by disconnecting the positive battery cable and connecting a volt meter between the disconnected cable end and the battery terminal, which appeared to confirm a voltage draw was present. We then proceeded to the engine compartment main fuse block at the driver side fender well and removed one fuse at a time until the voltage draw disappeared. The 50 amp fuse in question powered the fuse block in the cab under the dash, so we reinstalled the 50 amp fuse and redirected our focus to the under dash fuse panel. After removing the fuse for the “Battery Saver” circuit, the voltage draw seemed to disappear. Since the battery saver circuit is designed to stay on for awhile after the ignition key is shut off (which would naturally cause a short term draw), we decided to go back to the beginning and check the battery. With the battery removed from the vehicle at full charge, we performed a load test. Although the battery seemed to do o.K. On the short term load test, it would very slowly lose voltage over an extended period of time and drop well below 12 volts when it was not connected to anything. Although the battery was only a couple of months old and didn’t initially seem to be the problem, it was in fact defective. We replaced the battery with another new one, and the problem was solved! Lesson learned: When you have an electrical issue, ALWAYS fully check the battery before suspecting other components. NEVER assume the battery is good unless you can prove it.
Good Luck!