Help, Dead Suburban

[mehr4x4]

Hi, I'm new to this forum but not new to mechanics.

I have done quite a bit of searching on my problem and haven't found an answer yet. I have a 98 suburban K1500 The sub has about 160k and the engine has about 30k. A few times Lltely the sub has failed to restart after driving across town but after sitting for a little bit it would restart. Along with that the fuel gauge was flipping out and I had figured it was time for a fuel pump. The second to last time it left my daughter stranded it would hardly turn over. I found the positive battery connector corroded, so I cleaned it and jumped it and it started and I took it home. The last time it left her stranded I was out of town and it was left for almost 2 weeks in a parking lot with very cold weather. When I went to try to start it the battery again was quite week so I hooked up my dual purpose welder/charger on my service truck and the truck turned over quite well but it would not start this time. An odd thing this time. I have jump a lot of vehicles with this welder/charger with great success, it can sure crank out the amps but i'm worried I might have blown something(s) up. I noticed the hood light had blown out and now the fuel gauge was pegged up to way beyond max, straight to the right. I first thought the fuel pump had just gone completely out and the hood light had just blown out on it's own. I towed it home and let it sit. I just now pulled it in the garage to work on it and hooked up my OBD reader and it can't communicate with the sub but it has plenty of times before. All fuses are good and I have proper voltage and ground at the connector. There is a check engine light but it has been on all the time due to a catlitalist (sp) converter error that I hear is common and it ran great so I haven't felt like putting new cat's on just to make the light go out. I took the ECU out and took it apart. I couldn't find anything obvious but I could smell a slight burnt smell. I'm confused and frustrated. I was planning on giving this vehicle to my daughter but now it's dead. One other thing that may be related but I don't think so is out of no where it looks like the water pump is leaking but not from the weep hole like they usually do. This was a new pump when I put the crate motor in 30k miles ago. Please help. I'm just about ready to buy a used ECU from ebay along with a new fuel pump but I don't really have the money to just throw parts at it.

Thank you,

Eric

[Squirrely]

I would check fuel pressure, spark, etc... before I bough a new ECU.