Hi rotorheads,
I have a S3 body with a S4 13BT and my alternator stopped working. I was advised to check it by just starting the car and removing the positive from the battery and if the engine stops means the Alt is busted. So then i went to try and buy new S4 Alt but ended up being convinced to purchase a S5. I have not installed it yet. I was also told I needed a new rear plug. Will this be a simple installation for me once I have the plug etc. After reading posts on here i am concerned about ruining something or blowin something up!

Any advice appreciated.

Marcus

 

Disconnecting the battery on a running car-any car-is bad advise. Guaranteed to ruin a good alternator and possibly other electrical parts in car. With battery cable disconnected,the alternator circuit is incomplete and with nowhere for current to go,12 volt system can easily reach and exceed 100 volts causing damage to alternator and electronic control units,bulbs,etc.. Might want to reconsider where you get your advice. Using pictured diagrams,you can diagnose your car. The wiring diagrams show how to retrofit an S4 and S5 alt. in a 1st gen. The S4 is a direct bolt on with no wiring mods necessary. The S5 is also a bolt on but requires an S5 field plug and wire mods that are pictured in diagram. The S5 is more powerful than S4 alt,but do you need more power than a proper functioning S4 alt. supplies? The S5 alternator originally came with a serpentine belt style pully that will need to be converted to v belt type pulley and dual sheave v belt pulley is recommended to prevent belt slippage. Some pics of S5 install on my SE...