Car wont start. Bad ground?

[need4speed187]

Hello everyone I have a 92 talon tsi awd and the other day I went to the store, came back out and attempted to start my car.. then nothing no power at all so I get it to my friends house and we take my battery out and clean all terminals and while we were there we cleaned my iac motor because i have a problem with idle surge as well. so we put it back together and the car still wont start but guages come on very dim without me even trying to start it I even tried jump starting it, it didnt work and the battery is at 9 volts(I know thats low but I thought it should at least try to start), then when i turn my lights on it goes down to 3 so i dont think its the starter and i doubt its the battery i just bought it like a 2 months ago. By the way the car is pretty much stock with a boost controller, guage and intake. Any help is appreciated. Thank you.

 

[GVR4592]

If the battery reads 3 volts, it's dead.

 

[2gAWDTalon]

Take the battery back out and bring it to the local parts house. Most of the big chains check them for free. That is where I would start, it is free. If it is good, you know for a fact there is another problem. I bet that battery is bad...

 

[GST with PSI]

Load test your battery, I believe within lies your problem.