My 2008 Expy has just developed a problem, overnight the battery goes dead. I had the battery checked, shop said it was okay and recharged it for me - they said it was completely discharged. Anyway, any common things on our trucks that might cause this? Where/how do I start troubleshooting? Could the battery be bad but not showing such in a test? I have no idea how old it is, no date stamp I can find, Car Quest brand so it is not original to the truck.

 

Have you had the alternator tested? Most (all?) of the auto parts chains will test the battery and alternator for free. Advance Auto has a more extensive battery test than Auto Zone in my experience; AA can give you a printout with the voltage and CCA. If the battery and alternator turn out to be good, then the next step would be to find out what's causing the drain. However, a completely drained battery wouldn't typically occur due to a parasitic drain overnight.

 

Thanks for the help. I will have the battery checked again at a different place and then pull the alternator for testing if the battery seems okay.

If the alternator is bad, wouldn't I see a warning on the dash?

 

Pretty common issue is the rear wiper. Over time the mechanism gets crudded up and the motor doesn't read it's stop position properly, and it continues to try to park the wiper when it is already at the end of it's travel. Pull the fuse for it and see how things go.

 

You might be on to something with this idea. I noticed that the rear wiper is not working and is parked to right, and not down as far as it should be. I believe it usually parks to the left?

I'm going to drop the battery off today for another charge and test. I will pull the wiper fuse before install and see what happens overnight.

 

It is supposed to park on the left. I think that's your issue.

 

Charged the battery, pulled the wiper fuse and let the truck sit overnight. She fired right up! I believe the rear wiper was the issue, can anyone point me in the correct direction to fix it?

 

It would probably be easiest to replace the wiper motor (about $80) unless you want to try to disassemble the old one and try to repair it.

 

Thanks for the info. I will look for a new motor. I do not use the rear wiper, but my wife wants it fixed and she drives the truck more than I do, so I need to fix it

 

Before you go out and buy a new motor, open the glass, try and rotate the wiper arm by hand. If it's SUPER tight, no amount of new motor torque will fix it. I just did this on two Expy's with bad wiper motors, I think the strike plate got sticky enough to burn out the motor, then obviously, the motor and strike plate had to get replaced.

You will then be looking for a strike plate: 6L1Z-17C426-A

You may need a two leg puller to get the wiper arm off, but you can probably get it without the tool.

 

It is fairly tight, I moved it by hand back to where it is supposed to part and it did not move very well.

 

Lots of people here have taken both the motor side and glass side apart, cleaned and lubed, and been fine without ordering any parts.