I've been noticing after long runs, 2-3 hrs I've been getting Sulfer Smell through my vents (smells like somebody busted @SS) Couldn't figure out what was up. No Codes except yesterday BATT lite came on dash w/not charging message that scrolled across, lite went out & message went away. This happened a couple of times while in Drive but brake on. Never happened again. Today I get smell again.....I hear something sizzling after our trip to NH & the passengers side battery is boiling, steam coming from vent holes(handle hooks). Truck is an '03 w/76k on it......should I replace both batteries or just the 1. Someone else said to check the altinator to see if it's over charging. Has anyone else had these problems???? Any advice will be greatly appriciated.:(

your battery is going bad my 01 did that on the battery on the right side smelled like a fart i thought it was me at first but it started smoking in the truck have the batterys tested and the alternator

It could be your voltage regulator.

just had batteries tested @ Advanced Auto Parts, both batt diods where good, drvrs sd was 13.82 volts, pass sd 13.9 volts. They couldn't check alt w/both battiers @ same time but ALT said ok when checked separately w/ea battery......I have no quams about replacing both batteries but the voltage reg sounds like a good avenue to presue????? how do you check for that???

If those voltages were taken with the engine off then it must be over charging. You should expect about 12.6 - 12.8 V with the truck off. With the truck idling you should measure about 14 - 14.5 V.

Make sure you take the battery tray and inner fender out and clean any spilled acid up with some sodium bicarb and water. My passenger side battery leaked and acid ran down the fire wall, eating the paint off down to bare metal. Took me a couple of hours to clean, scrape, sand and re-paint.

I had to disconnect one battery to get correct reading on each battery. if one battery is good it gives a false reading on the bad one

Thanks Guys.....Truck died last week & replaced both batteries.....seems ok now.....dash voltage stays @ 14.1......should I be concerned that when I start the truck voltage reads 12.6 holds for a min then goes upto 14.1...2 ??

Thats pretty normal. My truck has done that since new.

The voltage jumps up when the glow plugs turn off after you start the truck. The length of time the glow plugs stay on depends on the temperature of the engine (colder=longer).