355 Battery is Fine But Car Won't Start...Starter??

Check the battery posts and terminals.
I assume you de-activated the immobilizer before starting the car.
Then monitor the voltage the starter when you turn the key on. How much voltage are you seeing?
If everything checked out, then the remainder is the starter.

 

What year is your 355?

 

Normally you have to push the button on the 'alarm' module to deactivate
Early 355s (2.7?) did not have an immobiliser
Check battery posts and grounds as yelcab suggested
Check voltage at the starter
Feed the starter with a separate battery if necessary

 

Another possibility is that you might have a dead spot on the starter commutator or bad brushes.

This has happened to my F355 Challenge car several years ago. Rocking the car while in gear (I used 2nd gear) moved the starter motor armature a bit and enabled me to start the engine.

Important: Make sure the ignition is OFF.

 

If your car has the starter relay mod, check the fuse located next to the relay.

 

Occasionally on my car (also a 2.7) I have to hold the key on start for a few seconds before the starter kicks in. No idea why, but usually only happens when the car is cold.

 

Be aware that whilst a battery might show over 12 volts, it doesn't automatically mean the battery is fine - It could have an internal fault that leaves it unable to produce enough amps to operate the starter motor.

A simple multi-meter won't tell you if the cranking amps are enough - The battery would need to be put on a dedicated battery condition tester to see if it's good or bad.

 

A '95 doesn't have a starter relay as standard. Seems odd that the tech would suggest this.

If anyone has added one, then it could be in the engine bay (although 5.2 cars have it bolted to the footwell relay panel).

If it's in the engine bay, it will be somewhere between this waterproof plug and the starter:

Image Unavailable, Please Login

 

Ian, that picture has zero dust, or rust, or paint chip, or scuff marks, or anything that suggests that you actually drive and use that car ... at all.

 

Indeed, but the previous owner left it in pristine condition (cosmetically, at least). I didn't want to ruin his fine work. I haven't washed the car since I bought it, 10 years ago. Just used a waterless cleaning product. If you look hard enough, though, you will see a layer of dust in the nooks and crannies. And if you compare it to Elliott's cars, it's a garbage bin.