2002 Avalanche Stalls

[james21]

My 23 year old Avalanche is having problems starting. I had the batteries and alternator replaced 3 months ago, the batteries were shot and the Ohio gen alt was 8 years old, so I got a new Ohio gen and tone starter batteries and one deep cycle. My mechanic said the truck kept drawing on the batts, so I know there is a parasitic drain.
Now I don't know if the battery and electric problem is the cause, but I've had to jump my truck every time to run it. The latest time took 2 sets of cables and a jump pack. I had to keep cranking it and applying throttle to get the truck to run. In drive it would be ok, but every time I shifted into reverse the rpms would drop to 0 and the engine would stall.

Looking for some help.
Thanks.

 

[Rassilon]

Many years ago with a Triumph TR7 (Over 30 years old & I'd always fancied one), I had similar issues due to the starter harness going high in resistance (Dropping Volts as a result), in the end I fitted a battery that was about 680CCA instead of 425\480CCA.

 

[Wpolonavyguy]

I'd try metering main battery cables, check the driver side door latch, then Sperry tech section has thread to find battery drain.
I added a second battery in my 07 luckily only issue I've had is driver door latches constantly crap out electrical switch telling truck drivers door opened.
Radio, accessories power & lights stay on until I flip latch & handle till decides to trip.

 

[james21]

I'm thinking my original dual battery setup is obsolete and perhaps part of the problem. Its about 20yrs old. Thanks for the help.

 

[Rassilon]

Might sound daft but have you tried, disconnecting\isolating the second battery from its harness & attempting to start & then using jump leads from the second battery to the main & attempting to start or is this what you've been doing\about to attempt.

 

[MS03 2500]

I'm curious James how many amps is that altinator putting out.?

 

[Randy]

I would make sure your fuel pump is working... Turn the key to the run position but don't crank it, at the same time listen under the truck on the drivers side under the rear seat area.. You should hear the fuel pump run for a few seconds and then stop, it does this to pressure up the fuel rail. If you don't hear it, then it's probably your in-tank fuel pump...