I picked up a new battery, a diehard with 750cca. As soon as I hit the starter, the battery drains, both battery cables and the starter get hot. I checked the grounds, they were all tight. no frayed wires, all fuses were good?

 

Just put a new starter in it no go. Im at a loss here.

 

Dead short somewhere. Trace it out with a DMM/ DVM. If it's not your starter, check your ASD relay and the entire fuse box by removing it and test for shorting.

That is a dead short to ground and was the reason why the battery and cables and starter got hot. It is shorted somewhere. It's just a matter of finding it.

 

Im hoping its the positive that goes from battery to starter, its definatly starter related the guages are working, as well as all lights, but as soon as I hit the starter everything dims and I get a huge voltage drop.

 

Your battery cable going to the starter is shorting out to ground somewhere between the battery and the starter. Trace it and look for melted insulation along the line. My guess would be right near the exhaust manifold or header pipe. This issue is way off from your original post about needing to give it throttle to start it. Now you are saying that when you hit the throttle it dies, where as before you said it wouldn't start without hitting the throttle. Which is it or did the symptoms change?

 

The truck started on its own at first, I let it idle for about 30 seconds and then hit the gas and it choked out. whenever I restarted it after I had to hit the gas to get it to fire. I drainded the battery cranking it, accidentally hooked my charger up backwards for about 10 seconds, pulled it off and it was cranking slow. I replaced the battery with one that has 750 cca, still no go, added a 250 amp boost, replaced the starter since the shop said it was on the fence when they tested it. Its still cranking slow, all lights work , guages ect. When I hit the starter I know I must have fried that cable with the charger, so once I get that figured out I can focus on the truck running bad part. A few people told me it will run bad for the first few minutes because the ecu needs to recalibrate to the different running conditions since the intake isnt sucking in oil and leaking. The check engine like did come on when it was idling.

 

Yes it is fairly standard that the computer needs to reprogram itself for the new readings it is receiving. You may have done more damage than just a cable if you hooked the charger up backwards and had it set to 250 amp boost and were trying to start it that way. have you tried jumping the starter relay and see if it turns over like normal?

 

No I didnt even think of that. I only had 50 amps when I had it on backwards, so I got lucky.

 

50 amps is way more than enough to fry your entire system if hooked up backwards. Since you said all of your gauges and lights etc. are working correctly then you probably did get lucky. Since you only have the major drain when trying to start the truck I am definitely going with starter cable is shorted out. Like I said and others follow it from the top down and look for where it melted the insulation and is grounding out. You could temporarily fix it by wrapping several layers of electrical tape over the melted section of insulation but I wouldn't leave it like that as the insulation on the wire is much thicker for a reason.

 

I just spent a few hours on it, the starter wire is fine I pulled it out, it has only .4 ohms end to end, and to double check I cut the ends off and it isnt burnt/melted insulation. I ran a jumper cable from battery to the starter, I still had the alt out and the starter was spinning faster and the truck actually started. It ran decent but it died after a few seconds. I put the alt back in, tried it again and just heard the solonoid click. When it clicks all power in the truck shuts down, radar detector in the cigar lighter dies ect. I think it could be that negative cable to the alt? The starter was hot when it stopped engaging so I stopped playing with it.