We have a 2002 Ford F-150 King Ranch. Here are the issues that we are having. When we now start the truck, the power locks automatically lock now. They didn't use to before. When you put the key in, the gauges go all the way to the other side, then back down, then to where they need to be. And the battery guage will read that the battery is fine too. We literally need to keep the truck running, gather everything and jump out as we are turning off the truck. Yes, we have checked the battery and the alternator and are both fine. Yes, now the radio and air is turned off when we go to turn the truck off. Then when we go somewhere, we jump in and pray to see if it starts. Someone suggested a recall and I'm not finding one. Oh and the horn recently died too.

 

The gauge comment indicates that the battery is not fine, but is actually on the way out.

How did you check that the battery is fine ?

 

Had it checked at autozone.

 

Ok, how did autozone check it.

I would think a but higher end shop doing a load test on it is in order.

 

They used their portable tester to check it while the engine was running.

 

But if it's the battery, why are the locks locking automatically?

 

Not sure what AZ tested, but that does not sound like a load test. Load test is removing 50% of the CCA of the battery for 15 seconds. This means you would need something that can remove 270 AMPS.

If the temps were around 60*, the voltage on the battery should not have gone below 9.5 V when the test was being done.

Power locks do not take anywhere near the AMP draw that the starter does.

The gauge sweep is a condition that happens with a low battery or after changing the battery ( should only happen 1 time ), this is how the truck calibrates the cluster when it gets power after having none.

 

What Sscully is trying to get you to understand is that the battery needs to be properly tested. If the yahoo at Auto Zone tested your battery with the engine running, then it wasn't properly tested (you have voltage because the alternator is putting it there).

You need a load test to see what the battery can stand up to and how long. I had mine tested at Wally World, the hand held said it was good-load test out of the truck said it was junk in about 3 minutes. Volts are only part of the testing it's the amps that count.

When the battery is low it will make the gauges sweep when you first turn on the key. Also when the battery is going bad it will make alot of weird things happen, think of it as starving your PCM, they can get pretty stupid without the proper power.

Hope that SPLAINS it for ya.

 

Thank you for your help. We went ahead and replaced the battery. Everything seems to be working better.