I have a 1 ton 2000 GMC sierra (old body style 99') 7.4 litre V-8 gasser with the allison 1000 tranny, 4x4. the engine will not crank over..
battery was dead so I charged it, batt was holding 9v, so i hooked up jumper cables to my new car, guage showed 12v, so I tried to start the truck.. the fuel pump, antilock brake system, and guages came on.. as well as the "check engine light", "service engine soon", and batt light... I ensured the trans was in park, even tried neutral.. no crank
I hooked up the mini scanner tool I have, and got no codes.. cleared the ECU/ECM anyways.. no crank
I also tried swapping out my starter relay with the A/C relay, and pulling fuses to the ECU/ECM for 20 seconds to clear any issues/codes.. no crank
my next option is to clean the battery cables & terminals (or replace the cables), and replace the battery... the battery is only 2 years old.. due for replacement, but I'm kinda broke right now (christmas)
the battery is one of those stupid side terminal ones with poor connections to begin with.. is there a top post terminal battery I can get to replace this POC? or will the posts hit the hood? recommendations?
this is a plow truck, single battery setup (at the moment).. and the fisher 8' plow when running the hydraulic pump severly drains the battery.. lights dim severely, been wondering about a higher rated alternator (factory is rated at 120-140amps), larger power cables... etc.. dual batt system...