'89 Bleeding electricity
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Junior User
Joined: Sep 2006
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From: Nebraska
'89 Bleeding electricity
1989 F-150, 4.9, 5-speed.
Pickup will bleed bleeed off charge from the battery when parked. Disconnecting battery always ensure a start but is a pain. Anybody know any neat ways of determining where power is going without checking EVERY circuit one at a time. Or if there is a more likely place to start (common circuits that don't shut off in these older horses). Thanks in advance
Pickup will bleed bleeed off charge from the battery when parked. Disconnecting battery always ensure a start but is a pain. Anybody know any neat ways of determining where power is going without checking EVERY circuit one at a time. Or if there is a more likely place to start (common circuits that don't shut off in these older horses). Thanks in advance
FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
Had a similar problem last year and it turned out to be the alternator. In my case I could not get more than 12v charge, and the battery would drain overnight. BUT.. a benchtop alternator tester at a local garage found the alternator to be good. After chasing my tail for a few days trying to find something else wrong, I changed the alternator and both problems were gone. The rectifier and regulator are internal to the alternator, so a fault in one of these will cause a battery drain.
Cargo Master
Joined: Nov 2006
Posts: 2,171
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From: Denton, TX
An alternator with this type of defect can be dangerous as it can overheat and catch things on fire. This happened in my Dad's '86, got so hot the plastic cover over the throttle linkage caught fire. Disconnecting the battery was the easy part to eliminating the heat. Putting out the burning plastic that was now drizzling on to other things was the problem. I took my cover off and never put it back on.
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From: Nebraska
Update
Thanks for the replies. I did just put in a new alternator due to a bearing failure in the old one.......but I'm not convinced that's the problem.
In disconnecting/reconnecting battery I have realized that as soon as the battery is connected (with key in OFF position) the fuel pump relay engages and pump runs momentarily. I believe that should happen when the key is turned to the run position. So what gives? Does this call for a new ignition switch?
In disconnecting/reconnecting battery I have realized that as soon as the battery is connected (with key in OFF position) the fuel pump relay engages and pump runs momentarily. I believe that should happen when the key is turned to the run position. So what gives? Does this call for a new ignition switch?
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From: St. Pete, Fl.
If you have not already tried this, it might be helpful. Disconnect the neg terminal clamp from the battery and connect a multi-scaled amp meter in series between the neg. battery clamp and the neg post of the battery, with the pos lead going to the clamp and the neg lead going to the battery. At this point, you will probably be registering a current flow (your stated problem). If you can get a friend to help you at this point, it will go much quicker. With your friend watching the amp meter, start pulling and replacing fuses at the fuse panel (under the steering wheel) one at a time. If you pull a fuse and the meter reading stops, you have just isolated the problem circuit. If there is no change, reinstall the fuse and move on to the next one. If nothing seems to stop the flow of current, try breaking harness connections one at a time. You will find the problem. With a friend watching and you doing the grunt work, it won't take that long for 99% of the problems. This can actually turn into a fun-way to chase down a problem. Try it for yourself. Good Luck!
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Maybe too late by now. One thing to check is your fuel pump relay. These are famous for sticking closed and draining the battery. Mine would do it intermttently and was blowing my mind. I just happened to hear the faint hum of the fuel pump runnig one day when I was parked in the garage.
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From: Nebraska
Maybe a relay.
Thanks to everybody for taking the time to reply on my thread.
Several of you got to talking about checking relays and telling of bad relays found on your rigs so I decided to fiddle with mine. Just this morning I found one of the relays on the driver's fender is broken. The plastic top is missing and has exposed the guts. I don't know which relay it is (the relays are just lying on the fender instead of being snapped into their nifty little brackets). Somehow this little bugger was still doing it's job apparently but when I remove it from the pickup and plug the battery back in the fuel pump doesn't run right away now. So I'm hoping maybe we've got the culprit. Sorry it takes me so long to follow your advice.....I run cows for a living, we've had a drought here and I've had to move about 200 miles from home to keep the cows fed soooooo no garage, limited tools, and it's COLD outside lately.
Thanks again
Several of you got to talking about checking relays and telling of bad relays found on your rigs so I decided to fiddle with mine. Just this morning I found one of the relays on the driver's fender is broken. The plastic top is missing and has exposed the guts. I don't know which relay it is (the relays are just lying on the fender instead of being snapped into their nifty little brackets). Somehow this little bugger was still doing it's job apparently but when I remove it from the pickup and plug the battery back in the fuel pump doesn't run right away now. So I'm hoping maybe we've got the culprit. Sorry it takes me so long to follow your advice.....I run cows for a living, we've had a drought here and I've had to move about 200 miles from home to keep the cows fed soooooo no garage, limited tools, and it's COLD outside lately.
Thanks again
