Chevrolet Repair: 2003 Silverado possible short?, digital volt meter, voltage gauge

Question
QUESTION: I have a 03 Chevy Silverado 1500 V8. recently stolen got it back with steering column busted. Inside the fuse box under the hood the ignition fuse missing. Replaced fuses truck started runs fine, charging system fine. When I put the truck into gear the voltage gauge drops to about 7 from 14 volts, lights dim truck wants to die. When I give it gas its fine but as soon as I let off the accelerator its drops again. this only happens when its in gear. Do you have any ideas. Thank you for your time.

ANSWER: Hi,

 It could be the alternator.  IF there is a bad winding it may only be charging adequately at a higher rpm. You should have a load test done as well as a charging system performace test.  A defective battery cell could cause this too. Make sure you have 12.6v to start with.

w

---------- FOLLOW-UP ----------

QUESTION: Wayne,
I took off the alternator and battery had them checked. The alternator is fine the battery not so good. Replaced the battery. The truck is still pulling allot of voltage when I put the truck in gear RPM drop and wants to cut out. Is there some kind of electrical component in or to the transmission that would cause this. Park and neutral truck is fine. Thank you so much for your time.

Answer
HI,

 There are plenty of solenoids and valves in the transmission but in order for a battery to drop from 14v to 7 that would take almost a 250 amp draw.
 Most automotive components are designed to run at a minimum of 9-10 volts so I would be very surprised if the vehicle was actually running at 7 volts.  YOu should hook up a digital volt meter to the battery and make sure the gauge is accurate.  compare the reading on your meter with  the one on the dash when you pull it in gear.

WAyne