help troubleshooting msyterious current draw
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help troubleshooting msyterious current draw
I am trying to trouble shoot a myterious current draw. The truck is a 89 F250 7.3. It appears to be charging properly as the voltage is around 13.6 -13.9 consistently, When the truck sits for a week the batterys are both dead. How should I tell if there is a current draw and where to test.
Thanks
Ken
Thanks
Ken
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From: Virginia
You can do the test below. If it lights up bright, look at the starter relay and see if you can determine where the alternator wire hooks up. There should be some other smaller wires there too. You can take these wires off, and see if the light goes out. If it does, hook the one to the alternator back up. If the light lights up, you know your alternator has a problem, even though it charges(leaky or shorted diode).
If the light only lights up when you hook the other wires up, then you know the problem is eleswhere in the truck, and then you can pull fuses to see where it is. Make sure all the doors are closed, hood trouble lights disconnected, etc. when doing this test.
If the light only lights up when you hook the other wires up, then you know the problem is eleswhere in the truck, and then you can pull fuses to see where it is. Make sure all the doors are closed, hood trouble lights disconnected, etc. when doing this test.
Fleet Mechanic
Joined: Aug 2002
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From: Swansea SC
Amperage Draw
Back, franklins right , thats a good place to start.After reading your post it reminded me of my battery drain a few years back. My drain was a relay (choke) that stayed charged constantly.I got lucky when troubleshooting this problem.1985 f150 with an electric choke switch going to the relay was stuck closed.Problems are pesty and i knew my current drain was a good draw caused it drained my batery in 2-3 days.Having an amp meter hook up in the possible circuit can tell u alot, igniton off and truck doors closed and hood closed( if there an under hood light) only drain should be from your radio clock and memory .I know its not alot of help cause u still have to find the problem circuit Good luck TR
Fleet Mechanic
Joined: Aug 2002
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From: Swansea SC
Back , in my haynes book (which) doesnt included diesels(even though they have prints) ,yellow wires go to-eec power relay and also fuse #1 , also igniton switch, and also trailer lights marker lights . Dont let this confuse u this is only the begining where u trouble shoot. Alot of people start speculating when they are troube shooting .Do u have prints?haynes book . Now is the time to separate these circuits , be patient , i know its a pain. and with time u can find this drain Good luck TR
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From: Easton,Ks
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The problem goes down the tubes.
Well I traced it down to the fuse that has the radio, interior lights, and cargo lights. With everything removed I still get a current draw.
Any ideas.
Well I traced it down to the fuse that has the radio, interior lights, and cargo lights. With everything removed I still get a current draw.
Any ideas.
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From: Virginia
Originally Posted by backhoeken
I do not have a trouble light but a digital volt meter. What should the normal draw be 1 amp of .5 amp......
Are you sure there is not a glove box light or a console light on somewhere?
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Narrowed the problem down to the yellow wire that supplys power to the interior lights, radio, instrument cluster.
On a side note with all the cables disconnected from the starter relay there still is a .279 mA draw. I assume this is coming from the starter as that is all that is left connected.
When I connect up the fuse that goes to the interior light, radio, inst... the draw goes up to .985 mA. Tracing this down a little further if I disconnect the radio the draw drops to .279 mA.
Is this a normal draw?
Does anyone have the wiring diagram for the radio?
Ken
On a side note with all the cables disconnected from the starter relay there still is a .279 mA draw. I assume this is coming from the starter as that is all that is left connected.
When I connect up the fuse that goes to the interior light, radio, inst... the draw goes up to .985 mA. Tracing this down a little further if I disconnect the radio the draw drops to .279 mA.
Is this a normal draw?
Does anyone have the wiring diagram for the radio?
Ken
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Joined: Jan 2001
Posts: 57,005
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From: Virginia
On a side note with all the cables disconnected from the starter relay there still is a .279 mA draw. I assume this is coming from the starter as that is all that is left connected.
Do you know if you have an external amplifier with that radio? Sounds like the radio may have a problem internally.
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From: Virginia