Morning folks

S type v8 1999 Auto

went to go out this morning and the car was completly dead, The car unlocked fine. Went to put key in ignition, No power. Starts fine with jump leads, But when i go to press any electrical switches like electric window the car just dies and won't power up again. This was after a drive for 5 mins around the block. I'm assuming alternator? Does anyone else have more possible diagnostics please

 

remove, clean battery clamps

 

5 mins would not recharge battery so could just be a flat/dead one.

Try 12 hrs on charge.

 

+1. While you're at it, check the battery with a voltmeter. If one cell is dead, it'll read around 10.8 volts, even though alternator will run at over 13. When you attempt to restart, all that will be available is that 10.8....insufficient to start.

Just went through this on my truck before cold weather hit.

 

All sorted. Was indeed a dirty terminal on the battery. Had a friend come round with a voltmeter. As the prong from the voltmeter was placed between the battery and the terminal, All the electrics came on. Nice easy fix. Cheaper than altanator replacement which new is between £300-£400! Let's hope the altanator never packs up

 

Excellent!

Get a scrap one if it does.