Hello and thank you for the opportunity to assist you. My name is ***** ***** I will do my very best to answer your legal questions.
In order to successfully fight the ticket, you need to present enough evidence to convince a judge that the truck ran the red light, and that you would not have pulled out if the light were not red. In other words, convince the judge that the truck driver, and not you, was negligent. If you can prove that the light was red, then you should win since you would have been reasonable to assume that traffic was clear.
As for how to obtain evidence, that is the hard part. If there were witnesses, then that would be helpful. Or a traffic camera at the intersection (you can subpoena the footage from the city). If you have no witnesses or other evidence, then you will have to rely upon your own testimony. Obviously, it will be much more difficult to win if the only evidence is your testimony, though you may still have a chance if the officer didn't see the accident, and the other driver doesn't appear in court.
Does that answer your question(s)? Please let me know if you need clarification, as I am happy to continue helping you until you are satisfied. Also, please remember to provide a positive rating via the stars (and note that your positive rating is the only way that I'll get credit for helping you, so it is much appreciated!). Thank you. :)