(03 peterbilt 379 old werrner truck new inframe 100.000 miles 13 speed) Got new batteries 1.5 year old ,
same 1.5 year old.
Summertime 4 days later dead batteries ?
Winter below 40 2 days dead.
Hook up jumper cables and wait 2 min and bam starts right up.
But the Alt guage shows nothing ,i give it a thump on the fuel pedal and guage gos to normal 13 to 14 and lights get brighter.
Any clues would be appreciated.
Find and check ALL your grounds!
Engine to chassis
Cab to chassis
Batteries to chassis
Just because a connection is tight doesn’t mean it’s making a good electrical connection.
Checking grounds on an older truck means completely disconnecting, cleaning and reconnecting all the stacked wires, using a multimeter set on continuity is the final step.
Make sure you have as little impedance as possible, “0” is what we are looking for.
Verify if possible at both ends of the cable in question, it’s not uncommon for an older cable to have a break inside the jacket where you can’t see it.
Some older style alternators have a small wire to the regulator, make sure this is making a solid connection, it is what triggers the regulator.blairandgretchen Thanks this.
I dunno if it’s an option for you, but keeping a battery tender on when not in use really REALLY helps batteries.
I just changed mine today after 3 and a half years. When the big motor isn’t turning, the generator is, and when it’s home it’s on shore power with a trickle charge.
Interstate batteries, 950 CCA. Less CCA the better - lead plates are spaced further apart than 1000+ CCA, less chance of freeze/heat/warp/ contact.InTooDeep Thanks this.