Battery Draw/ No Start

After 5 Trips To The Dealer, About 10 Months Ago, My Car Needed A Hvac Control Module Replaced. Now I Am Having The Same Problem With A Battery Draw, So I Started To Pull Fuses, Found 9 Fuses That Had A Constant Draw, But The Ones That Concerned Me Was The Amp And Radio Fuse In Backseat, And The Dic Fuse In The Front. Every Time I Start The Car The Cd Player Would Cycle.(is That Even Normal?) I Need Some Help Finding The Problem. Any Suggestions?

I would think the head unit and DIC would need a constant power source such to not loose memory/presets. If you get a no start condition with full battery charge, I would look into a faulty ignition switch.

Joel

I would think the head unit and DIC would need a constant power source such to not loose memory/presets. If you get a no start condition with full battery charge, I would look into a faulty ignition switch.

Joel

Hello, not to jump forums but u said what i have, strong battery w/ no starting, dinging, nothing. how could one go about to verify if that is my issue. It ran great yesterday, this morning go to start it, and nothing. I put a new battery in 6mths ago cuz it was original 02. and it did that 2x's so i figured the battery was going bad and bought this new one. Its my wifes truck an its gettin to be cold here in WI so i'd hate to see her stranded. If u could tell me what to check that would be great. There is warranty on it, i bought an after market one but it covers everything w/ a 100.00 deuctible(not wynns they suck) its a different one. Thanks!!

TrailBlazers have a body computer. There are many systems that always have power. They are sleeping till a signal from the bcm or other input tells them to turn on. Keep this in mind while you are tracing down your problem. Make sure that your ignition is turned off (really off, not just the key is out). If your PRNDL is lit, it is not turned off. Check this often. The ignition switch/lock cyl stick some times.

Rob

TrailBlazers have a body computer. There are many systems that always have power. They are sleeping till a signal from the bcm or other input tells them to turn on. Keep this in mind while you are tracing down your problem. Make sure that your ignition is turned off (really off, not just the key is out). If your PRNDL is lit, it is not turned off. Check this often. The ignition switch/lock cyl stick some times.

Rob


Ok, This morning I went to start it and it started but the gauge read about 12(amps volts I dont remember which one) for about 10 sec. and then the lights flickerd kinda like they got brighter and then it jumped up to 14+ where it normally sits......battery or alternator?????

How old is the battery? The dash volts gauge is not an accurate instument, but if your lights dimmed well after the engine was running, you might have a bad alternator. Very common on GM's. The internal voltage regulator is what usually goes out on them. As far as testing the ignition switch? I'd have to refer to a decent manual. Never tore into one on a GMT360. It's in the steering colm near the key cylinder. Another harbor freight tools quality part.:rolleyes: You usually get a full power but no start and various dash lights condition with a bad ign switch.

Joel

FYI, I don't know what it is, I am two for two where the positive cable was overtorqued into the battery terminal. This caused a slow leak that started to corrode under the red rubber cover making power flaky/questionable.

If you just changed the battery this should have been seen and the terminals cleaned up. However I have had a battery in my Chevy truck that had both posts, side and top. The side post had leaked due to over torque and stopped working, while the top post still worked. I ended putting jumper cables from the top post to the side post connection to get it started.

A quick assesment of a alternator is to take a screwdriver with the engine running and touch the flat to the nut on the center of the alternator. This is dangerous with the belt and fan moving! If the alternator is producing power, there is an electromagnetic field generated and the screwdriver will be pulled to the alternator center. The field strength is proportional to the work being done, it won't be too strong, but should be noticable.

Ok, This morning I went to start it and it started but the gauge read about 12(amps volts I dont remember which one) for about 10 sec. and then the lights flickerd kinda like they got brighter and then it jumped up to 14+ where it normally sits......battery or alternator?????

Funny... (not so funny actually :frown: ), I just noticed my 2005 @ 26Kmi doing this exact same thing on a cold start (10-20degF ambient). Truck starts right up, dash backlights dim, as does radio display, volts gauge reads (as far as I can tell) around 12VDC. Then the dash brightens up and volts gauge goes to just above 14VDC, where it normally reads while running. No DTC's, no other concerns, etc. Strange. Very strange..:uhoh:

Joel

This sounds similar to a no-start condition that left my wife momentarily stranded this weekend. the radio showed a message of "amp needed" and the usual chimes were oddly disjointed. Eventually, after repeated attempts, it started and ran fine. When I checked it out, I hit the memory button for driver 2, to move the seat back, and it moved a fraction of the distance required before cutting out. I had to push the button half a dozen times to complete the move. The start seemed a bit sluggish, but it did start. The volt gauge would not sit still, it was constanly flickering between 14 and 17 volts, regardless of RPM. Also noticed the headlights flickering while driving, and the windows moving exceptionally slowly when the truck isn't running.

I'm thinking it's something to do with the voltage regulator, or maybe the battery.

Just heard thru the grape-vine that the voltage jump after a (very) cold startup is perfectly normal for the GMT360 chassis. Apparently, the PCM takes the alternator 'off-line' for 10-30sec to lessen the load on an extremely cold engine. This explains the ~10 to 14.4VDC jump you see on the dash gauge and see/hear from the dash lights and heater blower. Basically, you run on battery power alone for a few seconds after a stone cold startup.

Joel