There is a plug on the back of my alternator (stock S4 alt). It plugs into the alternator housing and its a 2 wire plug attaching to the main wire harness. What does this do?

Thanks

 

Ok, since nobody answered, I looked it up in the wiring diagrams in the FSM. It looks like that little plug connects the alternator to the alternator warning relay in the ECU.

If anyone has evidence to dispute this, please speak up.

 

I understand that this plugs Into the Voltage Regulator.

 

Jeez I wish more people did that...
You are correct.

 

Thanks NZ. So I can unplug this, install the haltech harness, and the alternator will function properly without that little plug right?

 

You've got a s4? The only thing you'll need to take care of is the Alternator Wires - you'll need to cut them out of your S4 Harness and rerun them. It's pretty intuitive once you get the Harness split open. In the S5, the charging Harness, as it's called, is integrated into the Front Engine Harness (driver's side harness).

 

When I went out to the car, I had noticed that these wires do not go to the ECU, but to one of those other mysterious plugs under the dash. I did what you said and cut open the harness to reroute these wires. Thanks for all the input.

 

They go to the CPU, not the ECU (I missed that before). Check the wiring diagrams again.

 

NO.

Why are you messing with the plug for?&nbsp I believe that plug goes into the power harness which is separate from the engine harness?



-Ted

 

Stock S4. Yes indeed that connects to the regulator. ReTed is also correct. Why are you messing with it. It has nothing to do with a Haltech installation.

 

that plug is very important for proper operation of the charging system.

For more info on alternators,
check:

http://www.vtr.org/maintain/alternator-overview.html

that's a Triumph page but all alternators work the same.

hugues -