Battery will not charge-1999 Ford Explorer Limited V8 AWD

[HenryTS77]

Ok - first I know this topic has been covered on the past but did not seem to cover this so my apologies for the duplicate but people have been so helpful in the past. I live in Central NY and although I have a driveway but I have to work outside - brrr :-( so I would like to know the priorities to check. My truck runs fine otherwise but suddenly my battery went dead. I have a portable booster which starts the truck easily and it runs fine but when I shut down even after a lengthy run it will not restart. I can even run the truck at night with headlights on , heater on high , rear blower on high, electric rear defroster on without so much as a glitch and the voltage gauge on the dash stays mid range. I have swapped the battery with a neighbors known good battery and it eventually dies with the same results and the neighbor recharges it and it is fine for him. To me this seems the alternator should be fine or else I would not be able to drive the truck at night and the voltage regulator should be ok based on the gauge on the dash. Any ideas would be greatly appreciated

 

[71cutty455]

Check your battery cables to see if they are corroded and check your grounds as well. Either one could cause problems like you describe. Also don't forget that most auto parts stores can check the alternator/battery/starter for free to verify their condition.

 

[jahzwolf]

I am thinking the regulator is bad or there is a large fuse blown

 

[jahzwolf]

Look at that Mega Fuse the truck would run but not charge the battery
Here is the schematic

 

[HenryTS77]

Thanks for all the replies . As I mentioned before the weather up here is lousy but I did get a break today and was able to check the mega fuse ( they hide it well) which I tested with an ohmmeter (after removing one of the cables from the fuse of course ) and it showed the fuse to be good. However I noticed considerable rust/corrosion on the fuse terminal (more than likely the other one is the same) so that would no doubt introduce resistance into the circuit. I know I could take the fuse out and sand both terminals but since they are relatively cheap at $6.50 would I be better off replacing it? Now that I think about it this has been a slowly building with harder starts until one day I left my lights on while in a store for 5 minutes and it would not start. I had to call AAA ( I left my booster at home ) and the tech tested the battery and charging system and said they were fine but since then Ionce I shut the truck off I need to use the booster to restart it.



I got chased in the house by weather today but Tuesday they are predicting a heat wave (40 - woohoo) and decent weather so I will get out there and check/clean all connectors and see what happens

 

[jahzwolf]

well it is clear that any corrosion will cause you issues remove it all everywhere you find it in the charging circuit ..

Then buy yourself a cheap 15 dollar multi-meter and measure the voltage at the battery while you are have about 2000 rpm, then shut the motor off and measure there should be at least a 1.5 volt difference .. also see what it does when you start the car if it holds at least 11 volts while cranking .. if you do i would be looking at the cables to the starter for corrosion as well...

 

[dersch6221992]

I had the same problem in my mountaineer... it would sit for less than 12 hours and BOOM it was dead. i took to store said battery was good, and alternator was good. I ended just going to walmart and buying a new battery and havent had a problem since... i guess it was the 4-5 year old battery. so maybe try replacing your battery.