So the check guage lights came on and volts dropped, replaced alternator and then the battery blew up.... replaced batteries and check gauge lights came on again and volts dropped again. I have code P2502 and I am stuck 5 hours from home, battery cables are clean and all connections are tight, cant get into see mechanic for a few days, need to get home, drove throug lots of mud and water, what did I ruin? any ideas??..

 

Check for power at the back of the alternator. You may have blown the 150A fuse for the alternator if there's no power there. Anything else is gonna take more diagnostics.

 

checked fuses all seem to be good, cant find fuse that is for alternator, I have no idea which fuse is for the alernator, which one is the 150A?
is it one of the big black ones?

thanks

 

how do you tell if the big black ones are burnt?

 

hey guys anymore info, i dont know what fuses to check, none of them say alternator.

thanks

 

Large fuse at the end of the fuse panel where the heavy guage wires come in at. IIRC. It bolts in with 2 small bolts.

 

I'm thinking if your alt fuse is blown.....you wouldn't have issues blowing up batteries.


I know which battery blew.

 

J........haven't seen it before myself......how do you know which one and why did it blow? Anything I should look for on my own to keep it from happening? I was thinking that the fuse blowing may have been an after result of the battery blowing. Thanks for any insight.

 

My $$ is on the right (passenger) side battery. Am I correct???

 

Still doesn't explain why....................

 

The battery blowing up would most likely be from a short. The current inside the battery and the chemical reaction would cause an explosion if the excess current remains on the battery for a while. Too many volts charging a battery would do it also.

 

just got home. yes it was the passanger bettery that blew up. actually boiled over pretty good. took to a mech in the crummy village i was stuck in and he did some tests on alternator and batteries. alt is good. passanger battery over charging. our guess was that a cable was busted, apart or loose. took off all the battery clamps which appered tight and cleaned them. put back on and all is good.

now i have another problem involving tps and apps sensor which i will post in 3rd gen. thanks for the help. guessing i now have spare alt. will test tomorrow. thanks again

 

You should replace the batteries in pairs. Batteries charge differently with age.

 

Ahh haa! Looks like your local boy nailed it. I would have gone one step further and removed the Alt output from the bat + terminal and soldered it into the cross cable that joins both batteries. Most of the time I see corrosion or poor connections causing this. The ecm was monitoring bat voltage... this monitoring originates at the drivers side batt harness. With a poor connection between the two batteries the ecm keeps full fielding the alt wanting to see an increase in voltage. The alt output, as you may have noted, goes directly to the passenger side batt. So here's the ecm charging to beat the band wondering why it's not seeing target....and the passenger side battery is getting the krap charged out of it. They pretty much made a "loop" out of the charging system. Anyone want to confirm this simply unhook the crosscable at your drivers battery, start the truck and monitor battery voltage with a voltmeter at the alt, passenger batt, and then the drivers batt. Just don't let it run too long. You'll see why when you see the output voltage.

 

J BODY , that is a great piece of information! Thanks so much for sharing it! I will definately look for some corrosion on mine!!!!!