[rdubb17]

After reading the instructions on installing this cutoff switch, I had some questions. I sent a note to Taylor but of course, heard nothing.

The step in question is:

Connect a jumper wire from the alternator output terminal to one of the 3/16” terminals. Use a minimum of 10-gauge wire for this connector (maximum current
20 amps).

My question is, is this 10 gauge wire suppose to carry all the load of the alternator output or is this truely a jumper wire? My alternator is suppose to put out 130A - haven't confirmed that with real word data. Also, will using this switch while the engine is running harm the alternator? I've heard of people blowing the diodes when using these switches.

[jsa]

http://www.taylorvertex.com/Support/pdf ... 113474.pdf

No it is not suitable for switching your alternator on the aux terminals.

[85GT]

What are you trying to do? Use it as a battery disconnect or an alternator shut off?

[rdubb17]

End goal is to be NHRA compliant with a battery installed in the trunk.
If the engine is running; you need to be able to depower the entire car via this switch.
I also do not want to harm the alternator in the process of turning off the switch when the engine is running.
I would say those are my requirements...

When I bring the car to the track, I don't want to fail inspection.
The funny thing is, there are multiple instructions floating around out there on this disconnect switch. Some say "aux" and some say "alternator".
I believe the paper instruction that was sent to me with the switch states alternator hookup terminal - I'll have to doublecheck tonight and if so, I will scan.

That said, for those who have this switch; have you been sucessful - if so; how did you wire?

[ironmanisanemic]

I've installed a similar battery disconnect before and it was the excite wire that was supposed to be connected to the output. The reason for this is even if the battery gets disconnected, the alternator can self excite and keep the engine running. By disconnecting the excite wire going into the alternator in addition to disconnecting the battery you will effectively kill the whole electrical system.

EDIT

Looking at your specific model it appears to be a basic battery disconnect, the extra wires are for an optional circuit that will stay powered even if the battery is disconnected.

For this specific unit make sure your alternator charge cable is on the battery side of the switch and not the vehicle side. Otherwise the vehicle will stay running.

[cgrey8]

Based on what you just described, I'm thinking your Battery and Alt should be connected together on this switch. Then the other side of the switch should go out to the rest of the car to land on the Starter Solenoid or whatever stud you have the battery and Alt landed to now.

With that, if you flip the switch while the engine is running, the Alt doesn't see an open load and thus you shouldn't harm diodes. The alternator is still connected to the battery as the engine RPMs drop. With both Alt and Battery severed from the rest of the car, all other electrical components should stop receiving power (i.e. EEC, ignition system, injectors, fuel pump, etc) which I'm assuming is the intent. The only exception would be if you had huge power-supplying devices in your car. The only thing I can even think that would cause any issues would be multi-Farad CAPs usually only used by audiophiles that need stable voltage fed to their amps. If this is a track car, my guess is you won't be loading it down with amps, subwoofers, and a couple 16oz aluminum can sized capacitors for this to be an issue. But even if you did, I can't imagine that they would have the capacity to power the engine for more than a few seconds.

And as said above, if your alternator has an excitation wire, you can keep the alternator on the car-side, and just kill the excitation of the alternator. However many alternators are 1-wire which means you can't differentiate between the load line and excitation line thus you are back to wiring it as I described.

[jsa]

I don't know the NHRA rules.

Chris's approach is how it is done satisfy CAMS rules.

Alternator shuts off as engine stops due to lack of spark and fuel. Alternator dumps load to battery.

That AUX is rated at 20A so it could control a relay if you really had to isolate the alternator power output. Alternatively It could also switch the dash light wire or field wire mentioned above.

[rdubb17]

I ended up using the exciter wire for the Alternator - works but voltage is not nearly as stable as it once was.
I'm only guessing it's because I have added 40ft of unshielded wire to the circuit but haven't yet validated my suspicions.

[EDS50]

Your supposed to use the alternator 12v key on source which is the green with red tracer wire located in your original "D" shaped harness plug for the battery switch to properly turn off the alternator feed when the battery switch is turned off. You can also wire your 12v key on lead to your fuel pump relay to these terminals as well. This is how I installed mine is NHRA legal.

vcm_s_kf_repr_671x772.jpg