Need assistance please
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Need assistance please
I have a 1986 f150 4x4 5.0l 2bbl carburetor. I just got a new battery, new alernator, new vbelts, and now my battery is running at 11.99v and does not have enough amps to start my truck without jumping it. My alternator is charging my battery. There is no parasitic drain when parked. Just today my tach is stuck on max rpm(6000) and will not move even with battery cables Removed from battery. Please assist me in what I can try next to figure out why my battery and tach are in the state they are in! Thank you
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
11.99 is "dead" for practical purposes. The resting voltage for a fully charged maintenance battery is 12.65 volts, a few tenths of a volt matter a great deal with an auto start battery.
To fully charge a battery requires about 2 volts above the resting voltage - so you want to see over 14 volts with the engine running at a fast idle, or more depending on temperature.
Get the battery on an outboard charger till you get things straightened out. Here are the checks to perform:
http://www.aa1car.com/library/charging_checks.htm
To fully charge a battery requires about 2 volts above the resting voltage - so you want to see over 14 volts with the engine running at a fast idle, or more depending on temperature.
Get the battery on an outboard charger till you get things straightened out. Here are the checks to perform:
http://www.aa1car.com/library/charging_checks.htm
Cargo Master
Joined: Apr 2003
Posts: 2,408
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From: Parkesburg PA
What's the voltage running? If it's not 13.9-14.5v you may have a bad alternator. Are both plugs plugged in to the alternator? Is your alternator internally or externally regulated. Internal will have two plugs, external will have a plug and a screw lug. If it's external, how's your regulator?
pedant
Joined: Jan 2008
Posts: 23,576
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From: EXTREME southwest CT
You have a 2G alternator.
Did you replace the charging plug of the harness, as detailed in the Ford TSB?
Every time the charging system is serviced this pigtail needs to be changed because they become corroded and melt internally.
Sometimes they even catch the harness on fire.
Did you replace the charging plug of the harness, as detailed in the Ford TSB?
Every time the charging system is serviced this pigtail needs to be changed because they become corroded and melt internally.
Sometimes they even catch the harness on fire.
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From: Denver Metro Area, CO
The connections *to* the alternator could very well be your problem, do as Jim suggests and at least look into that.
The tach is almost a different, unrelated problem.
What is the voltage at the battery with the engine running?
The tach is almost a different, unrelated problem.
What is the voltage at the battery with the engine running?
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pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
Tach is pinned and remains so with the battery disconnected???
I think it is just a bad gauge.
2bbl carb on an '86 5.0 F150?
I was under the impression that 1985 was the transition year and only 4bbl 351 HO and 7.5l trucks over #8,500 were carbureted in '86 &'87
Has someone done a swap and mucked about with your wiring?
I think it is just a bad gauge.
2bbl carb on an '86 5.0 F150?
I was under the impression that 1985 was the transition year and only 4bbl 351 HO and 7.5l trucks over #8,500 were carbureted in '86 &'87
Has someone done a swap and mucked about with your wiring?
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