Computer ground draining battery
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Computer ground draining battery
My battery kept going dead so I put a little light up probe in series between the negative battery terminal and the negative battery cable. It glowed a little bit showing that something was pulling power even with the key off. I pulled the fuses one at a time and even with every single fuse out of the truck it was still pulling power somewhere. I finally disconnected the ground wire for the computer (black with green stripe) from the frame and that was it.
Can anybody tell me how to fix this problem?
As a sidenote, I put the damn thing back a while ago, the previous owner had it disconnected. I was trying to pull codes in my code reader wouldn't work. Come to find out it was because this wire had been cut. I guess now I know why.
Can anybody tell me how to fix this problem?
As a sidenote, I put the damn thing back a while ago, the previous owner had it disconnected. I was trying to pull codes in my code reader wouldn't work. Come to find out it was because this wire had been cut. I guess now I know why.
Lead Driver
Joined: Jul 2009
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From: Sheffield, AL
Dr. Johnny Fever, I believe I have a computer from a 1986 F150 with 4.9L and C6. It was a 2 wheel drive, if that makes any difference? The truck had only 61K miles and was running. It had belonged to a local utility company and was parted out. If I can find it, and you want it, you may have it for the actual cost of the freight.
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Dr. Johnny Fever, I believe I have a computer from a 1986 F150 with 4.9L and C6. It was a 2 wheel drive, if that makes any difference? The truck had only 61K miles and was running. It had belonged to a local utility company and was parted out. If I can find it, and you want it, you may have it for the actual cost of the freight.
Tedster9, i'm not familiar with the electrolytic capacitors. Could you tell me more about what this is and where I can find it?
Post Fiend
Joined: Apr 2002
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From: Waterloo, Iowa
Capacitors, widely used in electronic devices of all kinds. Most everything electronic today is pretty much bulletproof and lasts almost indefinitely, but not electrolytic power supply capacitors. Their failure mode is often to short out. They are inexpensive and fairly easy to replace. I would guess anything over 20 years old is easily a candidate for replacement simply from a cost benefit. A .50c capacitor takes out a $100 fuel pump or whatever, plus $400 labor, etc. You get the idea. Not saying this will solve your problem.
pedant
Joined: Jan 2008
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From: EXTREME southwest CT
Inside the ECM (computer located in the drivers kickpanel) there will be three light blue 'cans' on the circuit board.
When these leak their electrolyte, they not only stop doing their job, the acid eats up the traces on the board, destroying the computer.
Great pic in this thread, https://www.ford-trucks.com/forums/1...fried-pic.html
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Post Fiend
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Lead Driver
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From: Sheffield, AL
[QUOTE=Dr. Johnny Fever;16314509]1986F150six, that would be awesome! Thank you. I looked online and there didn't seem to be a difference in the computers between the 2 WD and four-wheel-drive any place I saw. The only differences were automatic transmission or manual and regular or California missions. So I guess it would work. I'd be really grateful for the help. I think I'm going to end up having to rewire a lot of this too. From my other thread there still a bunch of stuff I can't identify and don't know where it goes and it still in "limp home mode" I'm pretty sure.
PM me your mailing information.
PM me your mailing information.
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Thanks to 1986F150six I have a brand new computer. I opened the box box just in time for the bottom to fall out of the sky, It's pouring rain LOL. amazing timing. Times like this I'd love to have a garage!
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Ok, good news and bad news. I installed the computer that 1986F150six sent and my truck does idle a little better, so something is wrong with mine... but the short to ground is still there. It was raining and was cramped upside down with the doors closed so I was in a hurry and just unhooked the wiring harness and connected to the new comp. If anyone can tell me hw to get it out of the bracket that would be very helpful. I'm guessing once I swap them permanently I can open mine and I'll find the caps bad.
I did a little experiment. With the ground connected and no key in the ignition there is a current draw when the computer ground (actually, isn't this the ground to all the emissions components, including computer?). I disconnected the computer relay module and the draw was still there. I disconnected the wiring harness from the computer and the draw went away. Now I'm stumped again.
I did a little experiment. With the ground connected and no key in the ignition there is a current draw when the computer ground (actually, isn't this the ground to all the emissions components, including computer?). I disconnected the computer relay module and the draw was still there. I disconnected the wiring harness from the computer and the draw went away. Now I'm stumped again.
New User
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I use these on all my rides. They disconnect the battery and stop the drain. To reset it you can just push in the cigarette lighter or headlights or more. This will reset the connection and have power to start the vehicle.
Look around for a good price. I got mine from a boat supply company that had them on clearance.
PriorityStart Battery Saver - Stop Dead Batteries on Cars & Boats [Priority Start! Battery Protector]
I also like battery tenders
Look around for a good price. I got mine from a boat supply company that had them on clearance.
PriorityStart Battery Saver - Stop Dead Batteries on Cars & Boats [Priority Start! Battery Protector]
I also like battery tenders
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Ken Blythen
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
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Dec 17, 2008 02:49 PM