Hey all....Ok, just bought a 97' 12 valve 2500 xcab long bed. $3,000 (stole it). I had a voltage issue about 10 days after i bought it. Voltage gauge read 8. I replaced the alternator...worked for the first start up then after i shut it off i still had no voltage. I wired in an external regulator and bypassed the old one. WORKED GREAT thanks to the guys on here!! Started up for a day or so...then had no power. Had batteries load tested and checked....checked out ok, primary was a little weak but my secondary was fine. I put a new primary battery in and started fine. Then after sitting all night the voltage had dropped and something is draining my new battery????? My speedo, heater, fuel gauge does not work. I have checked grounds and connections.....what the heck is pulling a draw. Thanks for any help i get guys.

---AutoMerged DoublePost---

All grounds checked out ok...but now nothing. And my intake heater(below driverside battery) are clicking with whats left of my power.....CPS???? No voltage

 

do a parasitic drain test

 

yup, get an ampmeter and start pulling fuses one at a time.

if the batteries are good, check and see what kind of voltage drop you are getting across your power wires.

 

Pulled my cps. Looked fine cleaned it set it. I think I have **** batteries. Doing para test now...

---AutoMerged DoublePost---

Trickle charged 50amp. Truck started fine ....full voltage. Did not find the draw.....could an external voltage regulator draw while the truck is off

---AutoMerged DoublePost---

Trickled the bats.50amp. Started just fine . Running 14. Volts on meter. still can't find a draw.

 

A 50amp charger is not a trickle charger, that is a fast charge and that can cook your battery if left on too long.
Trickle chargers are offered in various amperages, between 1 and 6 amps, 2 amps being most common.

First figure out if your batteries are discharging.
Pull the battery cables and trickle charge each battery individually for 24 hours @ 2amps, remove from the charger and it should be 12.6 or slightly higher once pulled from the charger.

Let the battery sit for a few hours to cool after charging, when checked with a meter it should read 12.6 volts. Check the battery every hour and NOTE any drop in voltage.
If it reaches 12.4 volts that means it has lost 25% charge, if it continues to drop lower it needs to be replaced.

A healthy alternator will put out 14.6 volts running.
Once you verify the batteries are good test the voltage at the battery with the truck running.
You might need to upgrade your grounds.

Pull the caps on the batteries before doing this, top up each cell with distilled water only.
You can leave the caps off while each battery is charging. Topping up the battery with distilled water and applying a SLOW 1-2amp trickle charge will revitalize most batteries.
A good one to use is a 1 amp trickle charger intended for smaller batteries.
That offers better absorption, keeps temps low and prevents boiling.

 

Yes i know a 50 a. charge is not a trickle charge...What i meant was using a trickle charger at 50 amp. I put a NEW primary Battery in and truck was dead the next morning...thanks for the break down on the charge.