Porscheguy87

Hello all,

As title states I got a 1999 Boxster in today with a battery hooked up backwards. Replaced battery with new one hooked up correctly. I get all lights as well as interior and dash lights to come on. When ignition turned to start I get no start nor click. Ive replaced all blown fuses in driver footwell and checked the large fuse in rear trunk. Whats fried causing the no start? What else can I check?

Thank you for any help in advance.

Anker

My guess is that the starting problem came up before the battery swap.

I would check the clutch switch and ignition switch. Both inexpensive and easy to replace if you are a contortionist.

Macster

See if moving the key around while you turn the key to start the engine makes a difference. IOWs the ignition switch is suspect, even though the dash lights come on.

Check the security module located I think under the driver's seat. IIRC it has a fuse and if so and its blown the security module is getting any power and when the key is turned can't query the key for its RFID.

Anker

There are a lot of electronics that fry if they are fed reverse polarity, There's a good chance you have a bricked ECU and immobilizer.

Macster

There are and there aren't.

A co-worker's husband connected a battery backwards in his BMW -- this maybe 5+ years ago and the BMW wasn't a new model then but it still had lots of electronics/electrics -- and the only thing that happened was the speedo needle went around and was underneath the support pin. His solution was to drill a tiny hole in the plastic instrument cluster covering and carefully pick the speedo needle up with a metal sewing needle and put it back up where it belonged.

Not as far back as 5 years I seem to recall a thread here in which someone hooked up a battery backwards and the damage was slight.

Still hooking up a battery backwards is something to be avoided. I hope the OP is able to sort the car out.

C4 Pazzo

There are high amp fusible links in the power distribution module against the firewall in the passenger footwell.