battery light came on in 97 expy and I knew it had to be the alternator( heard bearings). Took it to autozone had it tested, was bad. Had a lifetime warranty on it, since I burned the last one up 3 yrs ago, giving a jump. installed the new one, tried to crank it up, didnt work, so I went back and bought a brand new battery. Put that in and it rode fine for a day. Battery light came back on stalled. Took alternator back to get it check, after I checked all wires running from it,they said it passed. Installed it again, cranked but can see voltage go down to 8 on the dash. They said bring expy to store to get them to check it. what could this be? Is there a fuse i could have blown fooling with the alternator before disconnecting battery?

 

How's the battery cables? Most neglected item in the charging system...

Might wanna replace both of them.

 

1. The easiest way to check your alternator is to disconnect the battery while the truck is running. If the alternator is good, the truck keeps running. If the alternator is bad, the truck stops running.

2. You can also use a VOM (volt-ohm-meter) and check battery voltage with the truck not running (~12 VDC) and running (~14 VDC). If there is no change in voltage, then your alternator is bad.

 

thanks, found out why alternator was not working properly. there was a 20 amp fuse in the primary battery fuse box on the passenger side firewall. It was blown. I replaced it, got another battery again(warranty), expy working OK. Only issue, battery light on dont know why. Got any ideas? Battery and alt. testing good.

 

NO NO NO

Do not disconnect the battery cable as there are sensitive electronics on board. That was fine back in the 60s, but not anymore.

To the OP, glad you got it fixed. I was just gonna suggest checking that fuse. I have had it blow on me on my car before and cause the same problems.