So the starter began to die on me so replaced it and she cranks like a hamster on meth again. All done, right? Yeah....riiiiiight...
Hooking up the 2nd battery cable on the driver side and I noticed it had a heavy spark, not your typical memory and such light spark. Key OFF.
Got inside to start it and the ABS light stayed on, but it fired. Called it a night. Ya know, all this happens the week the wife and the Tahoe are away and this is my only vehicle to get to work.
Batteries were charging the whole time R&Ring the starter. 10pm when I called it a night. 730 next morning, starter works perfect but truck will not start. Batteries at 10.8V and showing 15%, ABS light on and the relay was just clicking really fast while cranking. Left it charge up for a bit, now late for work...fired up and headed out with ABS light still on. Crappy brakes at first stop, pedal pulsated back at me, ABS light goes out...all is right again....for now.
Went back out this morning, fired right up, batteries at 95% and 12.3V, both. Started pulling relays and try to duplicate the problem...well...I did.
After pulling one relay at a time and plugging it back in with the key ON, I got my ABS back on and the no start clicking was back. Switched out relay for a new one but still no go.
Main thing I noticed besides the ABS light and clicking was my odometer when it does this dims down, especially at the ends of the numbers, 139,472...the 1 and the 2 were distinctly dim...anywho...
Relay number 302, POWERTRAIN (EEC) is the one I pulled and plugged back in to get the ABS no start to start again. Turned the key on and off a couple times and she fired right uo, odometer back to normal and no ABS light....looking for most likely culprits...like its lightly shorting out somewhere but I know thats a pretty busy circuit.

And GO!!!!

 

I'm stumped, but it really doesn't take much to do that.

I will throw one thing at the wall, have you disconnected your fuel bowl heater?

*edit*

Wait... the clicking... where is it coming from? Usually the VSM and/or alarm have issues with battery reconnects, triggering the alarm and flashing the lights/honking the horn. I get that every time on reconnect (I disconnected the horn from the keyless entry/alarm module because I hate the honk when it locks). It takes an unlock cycle of the key fob and insertion of the key to make the world right again.

All that to say, the clicking may not be related, it could be the VSM/alarm just repowering and assuming a theft attempt like it does.

Does your horn work?

 

 

Gonna grab the ohm meter and start pulling fuses to narrow down what circuit is having the issue. Doing a CVT trans on my sons Jeep in the morning so it will wait till that is done...unless i get up at 4 again...took Friday and Monday off since Saturday is my Bday and i haven't had a vacation yet...just what I wanna do...workin on my own stuff after working on everyone elses stuff all day...lol

Freaking HATE electrical...but for some reason I have a knack for it. Unwanted, of course.

Oh...the clicking is the relay...but its not the typical click, it sounds like a little machine gun and the engine will not fire until it stops...like I said I swapped it out with several different ones and no go...but its intermittent and that is messing with my diagnosis...

 

Intermittents DO suck.

Have you had a lot of rain lately? Windshields leak, drip down onto the back of the fuse block, cause all sorts of electrical havoc.

Pulling fuses is a tedious but sometimes informative diagnostic exercise. Look for rusty ones on the bottom row.

Happy Birthday.

 

UPDATE
Took the Ex into work with me Friday night. Used a REAL battery tester we use for AAA calls, the same one Interstate battery dealers use, and lo and behold I had a dead cell in the one battery.

They gave me a little bit of pro-rata so I saved like 50 bucks off new replacements. Almost guarantee the starter dying was killing the batteries, now 4 years old...6 year warranty.

So....new alternator, new starter, 2 new batteries, 3 inch lift...really need a break financially!!!

$1600 in less than 2 weeks is way too rich for my blood...thank God we dont have car payments!

Did a poor man's CAI too..hey...it works!

Thanks for the ideas guys....now if I can get the missing taken care of...NAPA valve cover gaskets???...wires are losing insulation...never again....buying the factory ones very soon..

FIXED! Thanks for the birthday wishes....send cash to:.... LMAO

 

This is WHY I needed my truck...yeah..work too

 

Glad you found it! I should know better, I have learned the hard way (meaning more than once) that proper start/running voltage is critical to computer-controlled ecosystems.

 

.... and good batteries are critical for keep an alternator from premature failure. Weak batteries are always "taxing" the alternator.