Try Pegasus Auto Racing
I put one as required (SCCA) in my Datsun 510 race car when I built it years back. I bought it from pegasus and as I recall it had good instructions. If you have a car with an alternator you need a special one with a resistor as seen below. I just had to replace the resistor as it was crumbling but never failed (some type of stone or ceramic??) and they sold it seperately. I have never had a related failure. Without the resistor they say you can fry parts. See paste below, Pegasus has a great tech dept you can call & talk to as well. Good luck
Matt
http://www.pegasusautoracing.com/
Email Special-#4430 Battery Cutoff Switch w/ Alt Protection
Regularly $54.99 - Now only $44.99 - You save $10.00! (for a limited time only)
We carry the highest quality master battery switches available. (See note below on how to spot a lower quality clone.)
Part No. 4430 has three sets of contacts for cars with alternators. The main contacts disconnect the battery while the auxiliary contacts disconnect the ignition coil and short the alternator output to ground through a 3 ohm resistor that is furnished with the switch.
A removable actuating key with splash guard, weather-proof cap, resistor and installation instructions are included. (Resistor lead configuration may vary.)
Question: How do I know if I'm looking at the genuine article and not a lower quality clone?
Answer: The terminals of the genuine highest-quality switches are plated with a tin-alloy and are therefore silver colored. Lower quality clones have unplated brass terminals. In addition, genuine switches are shipped with half-height nuts while clones are usually furnished with full height nuts.
Over the years we've heard about dozens of DNF's caused by unreliable master battery switches that were purchased elsewhere. Is saving a few dollars worth risking a DNF?
Click Here to view the wiring diagram.
Qty
Part No. EML284
Price Stock Status $43.99 In Stock