I have a 1996 GMC Sierra 5.7L v8. It sat for quite some time on a slow charge as my grandpa was not driving it. I inherited it and it did fine for a time unless it let it sit for more than a day, then the battery drained. Replaced the battery, found out the bolt holding the positive connection to the battery was stripped and not made for the battery...got a new bolt (the correct one). My grandparents said they replaced the alternator and had the electrical inspected to determine why the battery was draining and nobody can pin point it. I have noticed that sometimes if I wiggle either cable or tighten them just a bit the truck will start if it hasn't had too long to drain...well, that USED to work. This morning I went out to start the truck (it sat for 12hrs and the battery showed a full charge when I parked it the night before) and nothing, just the clicking sound of the starter (which has been replaced). Where should I start looking for the short? They swear the cables were replaced but I'm not sure how far (just the connectors or the whole cable?). They swear the alternator was replaced (but I'm guessing over 5 years ago). I'm at my wits end and carrying AAA card and a portable charger.

Rick Davis

• 97 Answers
• Posted on Jan 04, 2009

SOURCE: 1995 Suburban Electrical: Battery is being drained.

The alternator is usually the culprit when nothing else has been modified. However yo mentioned changing it. (actually the regulator inside the alternator usually fails and drains the bat when the engine is off) However there is a very common issue with mid 90's gm trucks, the brake switched go bad and cause the brake lights to stay on. Try lightly touching the brake pedal and see the lights go off after slowly releasing it. the fix is a new switch that fairly easy to replace . These are mounted on the brake pedal arm just above your foot.

Aside from these two issues, you will need to trace the problem to its source by taking items out of service one at a time by removing fuses. not that the engine computer and the radio will always draw power at start up and a tiny clock current thereafter. But there should not be anything else. The voltage guage is not very accurate in the dash. Use a volt meter to watch voltages unplug fuses until the voltage goes up. without the vehicle running, voltage should be between 11 and 12 volts on a charged battery.

And finally, check the grounding. There should be a ground strap between the engine and vehical body in addition to the battery cable. If this is broken or missing it will cause errant readings of voltage in the dash.

I hope at least one of these tips works out for you.

-FW

SOURCE: 1998 GMC Sierra radio and display stays on all the time

First of all...does your truck have the retained accessory power (RAP)? If it does, the radio would always stay on with the key off until you open the drivers door. If it does have RAP and the door pin on the drivers door has went bad, then the truck doesn't know that you opened the door and continues to allow accessory power (although it would still cut off after about 20 minutes). If the interior lights come on when you open the door, then the pin is ok. If the lights come on, it could be the RAP relay. If it has gone bad, it is possible it is stuck supplying power and needs replacing. The relay should be labeled in the fuse panel, and there should be other relays in the panel with the same part number. You can swap a relay for the RAP relay and see if it fixes the problem...if it does fix it swap the relays back and replace the RAP relay. If the truck doesn't have RAP then it is possible the problem is in the radio..if you have a friend with a GM car or truck close to the same year you could swap radios and see if that fixes your problem...should be pretty simple. pull the cover off the dash, it just clips on, take out a couple screws that hold in the radio, unplug it and plug in the other radio. sorry so long winded...hope this helps you somewhat.

SOURCE: 2001 GMC Sierra, 4.8 occasionally wont start.

sounds like starter solenoid,try cycling the ignition on start on start repeatly but do not go back to the off position off on start will activate the fuel pump repeatly and might flood it,with a faulty solenoid you can usually cycle the ignition repeatly and it will finally engage the starter

SOURCE: 03 GMC sierra 1500 sle wont start..

if your check engine light is on,yes.it worked for me.

SOURCE: battery drain 2001 gmc 2500 hd pickup

On cold start up, starts fine.When i start driving all gauges needles start to sweep.. fuel empty to full spedo 0 to 100 amps and oil gauges sweep back and fourth. emerg brake gos on and off message center flashes battery in red and yellow.
seems like its possessed..