I have an 03 GMC 2500Hd with the 6.6 duramax.....Sunday I left the house and went fishing ...when I returned to my truck both batteries
were completely dead...I purchased 2 new batteries. I drove home and on the way home I noticed the voltage gauge on the dash was staying around 12 volts. On monday I went to crank my truck and again both batteries were completely dead. I removed both batteries and charged them over night. On tuesday I bought a new alternator
and put in on. I reinstalled both batteries that were fully charged. I cranked the truck and the voltage gauge was reading right at 14 volts. so i turned off the truck thinking my problem was fixed. Two hours later both batteries are dead again. Any suggestions?
JA: Battery issues can be tough to diagnose - lots of things to consider. Luckily, the mechanic I'm going to connect you with knows all the tricks and shortcuts. Are you hoping to fix this yourself?
Customer: I need to after purchasing 2 new batteries and a new high output alternator.
JA: Is there anything else the GMC Mechanic should be aware of about your GMC?
Customer: No its beena good truck
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the GMC Mechanic about your situation and then connect you two.