tahoe wont turn over, PLEASE HELP!

[cockblocker]

Hey, My 99 tahoe started acting weird two days ago: after work I got in and she wouldnt turn over, after turning the key 3-4 times she finally cranked...didnt think anyhting about it. The next day she didnt it again, popped the hood and the "led" on the battery was completely out..ok so it's time for a battery. Went to walmart that night and bought a 875cca battery, threw it on the next day and didnt do a thing! still wouldnt turn over. took the battery back, they testing and it tested fine...got my money back. Took the battery off my wifes 96 grand prix, put it on and the tahoe fired right up...no problems. Ok so I thought the one from walmart was bad. drove to ruston, la...about a 3 hour round trip from home...no problems. this morning she didnt want to crank again...went to auto zone and bought a brand new 1000 cca battery, got home she still didnt want to crank. just now got finished putting on a new starter...nothing changed, damn thing still doesnt want to crank. No during all of this all the lights come on, alarm works, radio, AC..everyhting electrical works...just will not turn over.

Please can someone help me out here. it's the only vehicle we've got that doesnt have expired tags...plus today was the first day of my vacation...yay me!

THANKS!!!

[Daver84]

Sounds like your starter relay not working. Give it a good rap with a screwdiver while you try to turn the engine over. If that doesn't work check for 12 volts to the relay from the ignition switch. Check the wiring connections from the battery to the relay to the starter. Check the grounding at the starter also. Good Luck.

[cockblocker]

I did actually try hitting it a few times with a screwdriver the second day...now today I swapped it with the AC relay...(they're the same part numbers), but alas still nothing.

[cockblocker]

althought i did finally noticed that the fusable link between the hot side and the alternator has basically burnt in two...so i guess my battery was'nt really getting charged. but i dont see how that faulty wire being the cause of it not cranking... the cable running from the hot to the starter is perfect, no cuts or melted spots thru it. damn this is frusterating.

[cockblocker]

okwell, I repaired the fusable link...didnt help. this is getting very bad here. i just cant see anyhting that could be causing this. And to help clarify when I turn the key I hear the solenoid kicking in...just not the starter motor...almost like it isnt getting any juice.

[Daver84]

Check for voltage on the heavy gauge red wire on the starter solenoid post (should be there at all times) If not then there is a break/poor connection between the battery and that point or the ground connection to the engine block is bad. If its ok then have someone turn the key and verify the starter solenoid does in fact click on. If the grounding connection from the starter motor frame to the engine block to the battery negative post is good then either the solenoid contacts are bad or there is a problem with the starter motor. If the starter you put in had the solenoid on it then it's most likely a poor ground connection.

[cockblocker]

Thanks Daver!!, Last night I did slide underneath and have the wife turn the key...it is the solednoid clicking in, and the hot post is getting 12.47 vdc. Now one thing Im not sure about...the starter motor gets it's ground from touching the block right? I didnt noticed any other way, I wonder if I wire-brush the bolt areas if that might help. Last night I thought that iif I unbolted the starter and turned the key that would tell me if the fly wheel was causing the starter not to turn...as in locked up engine. To my thinking, the only other part in this loop that hasnt been replaced is the hot side cable. Im gonna call AutoZone and see if they can test this starter...I sincerely dont know wha else to do.