Electrical issues with my F150
#1
Electrical issues with my F150
I'm having a problem where I get no power anywhere to the truck after I try to start the truck. When I disconnect the battery and reconnect everything turns on, lights radio but when I try to start the truck again everything just dies again. Anyone know what it might be?
#2
#3
Yes, suspect the battery for an open cell strap or a cable is corroded at some point.
On a battery posts, a corroded or very poor contact can melt the lead on the post or connector from the heat generated passing a couple hundred amps but still be good enough to supply enough power to a minor load like lights etc.
To see this, look at the post and cable connectors for pock mark craters in the lead indicating melting has ocurred.
Always inspect the cables for under insulation problems.
Overall there is not that much to look at so you have to find it.
Good luck.
On a battery posts, a corroded or very poor contact can melt the lead on the post or connector from the heat generated passing a couple hundred amps but still be good enough to supply enough power to a minor load like lights etc.
To see this, look at the post and cable connectors for pock mark craters in the lead indicating melting has ocurred.
Always inspect the cables for under insulation problems.
Overall there is not that much to look at so you have to find it.
Good luck.
#4
Power is getting through the truck. I tested the power at different locations when the power shuts down and some of the truck has power and the rest does not. I tested around the primary battery fuse and I register 12v but it never makes it to the power distribution box. It almost seems as if there is a type of breaker that when there is all of a sudden a heavy load, it breaks and when the power is turned off it resets. Know of anything that might do that?
#5
Sometimes relying 100% on voltmeter will fool you when the issue is "load" related.
When you go to crank, the start relay pulls up and closes 'negitive' side of battery to the starter motor. You read it right, the neg side.
If the starter motor is locked up against the flywheel for instance a huge amount to current is drawn.
If there happens to be a poor conection to to boot, the rest of the truck goes without voltage due to the large "voltage drop" that can ocurr across a poor connection due to heating. After all 12 volts times 200 amps is 2400 watts of power as a ball park figure depending on the situation. This amount of heat can do funny things.
So again a voltmeter is not fool proof on such a trouble.
The mega fuse is not in the starting circuit but in series with the alternator so is not likely to act in such a manner.
Mega fuse at 175 amp rateing in not large enough for long term use in a starting circuit.
It's there to protect the truck from fire should the alternator or wiring go shorted to ground.
I just recently had a starter do this, kill all voltage due to the high current drawn at attempted cranking.
Changed starter problem solved.
I don't know what you will eventually find but you have to look at it by how the system works and do all the checks aside from just a voltmeter.
If you want to see the circuit, reference the Haynes book Page 12-17.
Good luck.
When you go to crank, the start relay pulls up and closes 'negitive' side of battery to the starter motor. You read it right, the neg side.
If the starter motor is locked up against the flywheel for instance a huge amount to current is drawn.
If there happens to be a poor conection to to boot, the rest of the truck goes without voltage due to the large "voltage drop" that can ocurr across a poor connection due to heating. After all 12 volts times 200 amps is 2400 watts of power as a ball park figure depending on the situation. This amount of heat can do funny things.
So again a voltmeter is not fool proof on such a trouble.
The mega fuse is not in the starting circuit but in series with the alternator so is not likely to act in such a manner.
Mega fuse at 175 amp rateing in not large enough for long term use in a starting circuit.
It's there to protect the truck from fire should the alternator or wiring go shorted to ground.
I just recently had a starter do this, kill all voltage due to the high current drawn at attempted cranking.
Changed starter problem solved.
I don't know what you will eventually find but you have to look at it by how the system works and do all the checks aside from just a voltmeter.
If you want to see the circuit, reference the Haynes book Page 12-17.
Good luck.
#6
I'm telling you. Listen or not. Put. The. Battery. On. A. Load. Test. It takes 5 seconds, if you know someone that works at a decent shop, I'm sure they got one, borrow it, if not I'm sure they won't charge or at least not much to test it at a shop.
I have had a volt meter F**K me over 1,000 times, actually it was me doing the F**King over because I was chasing down a dead end road.
Have the starter tested, I had one, one time, that pulled wAaaayyy to many amps and flipped the main breaker at advance auto when they tested it.
I have had a volt meter F**K me over 1,000 times, actually it was me doing the F**King over because I was chasing down a dead end road.
Have the starter tested, I had one, one time, that pulled wAaaayyy to many amps and flipped the main breaker at advance auto when they tested it.
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