My 1998 manual convertible won't start. This car is driven in Wyoming so it's stored for about eight months a year in a heated garage with a battery maintainer on it. The car has a little over 90k miles on it and has a Optima Red Top that is about four years old. I did a load test and the battery showed a drop from 12.6v to 10.8v, and my meter shows 12.6 volts at the alternator with clean connections on the terminals. I had noticed, this year, that the starter didn't seem to have the same "ummpphh" that it normally had, but it always caught immediately. I always turn on the ignition and let the gauges settle before I start with clutch engaged and the tranny in neutral. Last week I accidentally locked the keys in the car and had to "break into" my car. The theft alarm went off, but I did retrieve my keys and the car acted normally. I drove back home and parked in the garage and had driven the car several times after that. My wife and I took the car to the grocery store and when we came out and tried to start the car it acted like it had a dead battery - clicked, but no fire. We pushed it and dumped the clutch and it started and we drove home. At the present time it's still in the garage and won't even click when I try to start her. All the lights extinguish when I hit the starter, but the memory seat and gauges all read normal, but the instrument cluster is dark. The volt meter reads 12-13 volts. I tried to jump it with my battery charger at 30 amps, but got nothing. I read the DIC codes and got five C1255 - EBTCM Internal Malfunction, B0851 - Battery 1 Out of Range, B2605 - Seat Front Vert. Position Failure, B2606 Seat Rear Vert. Position Failure and U1160 - Loss of Communication with LDCM. I looked all the DIC's up in my shop manuals and none seem to be the cause of my frustration. I put a new OEM alternator on last year and I'm thinking that it's a bad starter - any advice/help would be appreciated. ..