Golf 2: What did I do wrong with the kill switch wiring?

[GTIspirit]

What did I do wrong with the kill switch wiring for my Mk2 Golf? When I throw the kill switch the engine doesn't stop....... I thought I followed these directions but I clearly didn't do something right.
http://www.improvedtouring.com/forums/showthread.php?t=20130

I have this kill switch:
http://www.pegasusautoracing.com/productdetails.asp?RecID=4913
Included directions are:
http://i27.photobucket.com/albums/c184/clmoore3rd/Electrical/Kill_switch_wiring.jpg

The alternator "field wire" is the small blue wire coming off the alternator, right? (The one I have the red multimeter probe clipped to in the picture below.) According to the Bentley, and verified by checking continuity, this wire goes to the instrument cluster. So I took this wire at the instrument cluster, cut it, installed spade and ring terminals, and put each side of this wire on the two small poles of the kill switch.
http://i27.photobucket.com/albums/c184/clmoore3rd/Electrical/20100916_1_DSC_4305_Kill_switch.jpg

I then routed a wire from the battery positive to one of the big poles on the kill switch. The second big wire went from the other big pole of the kill switch back to the starter, which is essentially the power distribution block because that is where the vehicle power supply is picked up.
http://i27.photobucket.com/albums/c184/clmoore3rd/Electrical/20100916_3_DSC_4307_Kill_switch.jpg
The smalles red wire, covered in convolute, presumably is the red wire coming off the alternator. The bright red wire going into the top of the picture is the main power supply to the harness. The biggest, out of focus, pinkish wire goes to one side of the kill switch. So my kill switch wiring was meant to follow Fig 2 of the diagram but I didn't get something quite right.......

Overall it looks like this:
http://i27.photobucket.com/albums/c184/clmoore3rd/Electrical/20100916_5_DSC_4309_Kill_switch.jpg

So when the kill switch is tripped the battery is taken out of the circuit, and I thought the alternator should stop charging when the field wire goes open circuit, but this clearly does not happen. I guess the alternator provides enough juice to keep the engine running at idle but Fig 2 shows the alternator charge wire on the other side of the kill switch from the battery, just like I did it, so I'm not exactly sure what I did.

Help is appreciated to tell me what I did wrong.

P.S. washer bottle is removed for a better picture.

[Greg Amy]

I just dug out my Bentley for the 1987 GTI 16V, and you just bisected...the wire going to your alternator warning light.

The Bentley shows two wires* going to the alternator: an 18-gauge blue wire for the dash light, and an 8-gauge red wire for power output. Apparently, the field sense circuit is internal to the alternator. So you have one of two choices:

- Wire your car up per Figure 1 above, bisecting your alternator output wire (the red one) through that smaller circuit; or

- Bisect a different wire that will kill the car absolutely, such as the fuel pump or ECU power.

The first option I'm not thrilled with; I don't know if those terminals are rated for the current the alternator could put out.

The second option would work; your fuel pump gets power from a G/BK 14-gauge wire off terminal 33/87 on the fuel pump relay connector; bisecting that would kill power to both the fuel and transfer pumps. The car, obviously, would die instantly.

Alternatively - and more attractive - for option 2 you could bisect the 12-gauge yellow wire off the ignition switch; that's the main keyed power output (circuit 15) that runs pretty much everything in the car (e.g., ignition module, distributor, coil, etc).

On the plus side to your "current" situation (har-de-har), you'll never see an alternator warning light... ;) Yes, you'll want to reconnect that wire...

GA

* Well, three really: the third "wire" is the ground to the chassis...

[GTIspirit]

I just dug out my Bentley for the 1987 GTI 16V, and you just bisected...the wire going to your alternator warning light.

The Bentley shows two wires* going to the alternator: an 18-gauge blue wire for the dash light, and an 8-gauge red wire for power output. Apparently, the field sense circuit is internal to the alternator. So you have one of two choices:

- Wire your car up per Figure 1 above, bisecting your alternator output wire (the red one) through that smaller circuit; or

- Bisect a different wire that will kill the car absolutely, such as the fuel pump or ECU power.

The first option I'm not thrilled with; I don't know if those terminals are rated for the current the alternator could put out.

The second option would work; your fuel pump gets power from a G/BK 14-gauge wire off terminal 33/87 on the fuel pump relay connector; bisecting that would kill power to both the fuel and transfer pumps. The car, obviously, would die instantly.

Alternatively - and more attractive - for option 2 you could bisect the 12-gauge yellow wire off the ignition switch; that's the main keyed power output (circuit 15) that runs pretty much everything in the car (e.g., ignition module, distributor, coil, etc).

On the plus side to your "current" situation (har-de-har), you'll never see an alternator warning light... ;) Yes, you'll want to reconnect that wire...

GA

* Well, three really: the third "wire" is the ground to the chassis...

Thanks for finding my problem. My mistake for assuming the blue alternator warning light=field wire. I had made that assumption based on my Rabbit which at one time had an open circuit on the blue alternator warning wire, which made the dash light on all the time and also made so the alternator wasn't charging the system. My bad for assuming the Golf was similar to the Rabbit.....

I could just bisect the T15 wire (technical speak for the ignition switch wire) at the right place, which would stop the fuel pump and ignition, thus killing the engine. The small poles on the kill switch should be rated for that. Ding ding, light goes on in head, if the engine stops then the alternator can't keep charging, and the kill switch isolates the battery from the vehicle, so the only place that would still have power is the hot side of the kill switch. I was originally thinking this option wouldn't work because the alternator would still keep charging the system, but the alternator can't keep charging if the engine stops..... :026:

So I'm leaning towards option 2.1 above, now to just find a suitable place to bisect the appropriate wire. (Kill switch is in the passenger compartment in place of the left side speaker/air vent. Protected through the dash panel sheet metal by two Hummel cable glands, I'm kind of anal that way. And at some point there will be a Mega Fuse right at the battery to protect the hot side to the kill switch, don't want that length of 2ga wire going live on something in the engine compartment. Did I say I'm anal about doing things right? :p)

[Flyinglizard]

Many Bosch alt will self field at 3000rpm without the field wire!!
That is why I break the fuel pump ground wire. Just pick it out of the hatch harness area, and run one wire to the master switch.
If you break the field wire, run the car at 4000 rpm and turn it off. It may still run for some time or until it returns to idle.\
It stops right now if the fuel is off...
Breaking the ground wire solves a lot of tracing, relay stuff also.

[Sandro]

The Blue wire actually tells the alt when to kick in, so cutting it doesn't do anything. The car will still run without it, just damage the alternator.


I have mine wired to the Coil wire, or as Mike said the Fuel Pump wire.

Mike brought up a good point about above 3000rpm. For this years annual they actually told me to rev the car past 3000rpm and then they flipped the switch, he mentioned the exact same thing as Mike.