Ok, so i was driving from New Hampshire to New York yesterday (about 5 hour drive) and it started raining after the first hour and didn't stop the whole rest of the way. when i got about halfway i stopped to stretch and shut the truck off. i stretched for five minutes, got back in, turned the key on (everything looks normal, voltmeter says "normal", nothing unusual), and after the "wait to start" went out, i turn the key and "click" is all i hear. the interior lights go real dim, the radio resets, the gauges shut off, and it was like the battery was completely dead. I tried to jump start it with the wife's expedition and it was like it wasn't even connected. so as a last resort, i had the wife push with her expedition, popped the clutch, and she started right up. as soon as she started, all the gauges went back to normal, voltmeter was at the "m" in normal, and all the lights and electronics worked just fine. i drive for the rest of the trip without shutting it off, and as soon as i get where i'm going, i shut it off and instantly try to re-start, and it does the same as before. I've had this problem before once about a week ago, but i didn't think anything of it. i just took the batteries out and had them charged at autozone, brought them home, put them in, and haven't had a problem until last night (the first time it rained after). I'm thinking it's something like a short or a bad ground, but that doesn't explain why it only does it when it rains... any thoughts????? I don't really even know where to start...

 

It's probably just the starter relay on the fender. You can jump the two large terminals and get the truck to crank.

 

I agree. Change the relay. Probably corroded inside and moisture is cause the connection to be worse.

 

When you took the batteries to Autozone, did they test them?

 

yeah, autozone said the batteries were both good, and they re-charged them both... i'm thinkin it's just the relay at this point... i went back out this morning and tried to start it and it was normal until i turned the key to start, then everything dimmed, etc. when i let off the ignition and it was in "on", i heard a rapid clicking under the hood, and when i looked, "relay 2" in the fuse box was the source of the click.... guess i'll take a trip to the parts store...

 

I've had problems in gassers where the tensioner pulley was just loose enough to let the belt slip when it rained and got wet. This would make the alt not charge the batteries properly, especially with lights, radio, defrost, wipers, etc running. Dunno if this is your problem, but it might be worth checking out

 

If the starter relay is not the problem it could be a bad starter as well

 

Yep, and check all your connections and grounds first (batteries, starter, relay).

 

well i guess she was just being picky, cause i went out today (first day it hasn't been raining) and tried to figure it out... first thing i tried to start it and everything went dead. popped the hood and checked battery connections and they seemed fine. pulled the cables off, and checked relays in the distribution box (1 & 2) and they still look almost brand new. put them back in, re-connected the batteries, tried to start it again and it fired right up. so my guess is that it just got some moisture in a connection somewhere and that was screwing everything up... thanks everyone for the help though!

 

Keep an eye on your battery connections as that is EXACTLY how mine was this spring when I went to start it after sitting all winter.

 

yeah, kinda freaked me out cause the first time i tried to start it today i checked the connections and the far positive connection was smoking... i guess it got some water between the cable and the post... lol

 

I told you

 

It is a problem I had too. It is a connection/ground for the wiper. It shares a ground with the computer. Our fix was to run a ground from the ring terminal where it attaches to the body straight to the battery. Hasn't done it since.