All is not right as I discovered the car is cutting off and on while the switch is on, kind of like a miss. Bypassing the switch and wiring the battery ground directly to the block as it was puts everything right. My buddy told me that I should have installed the cut off switch on the positive side...something about amps and volts, but now I think he may be correct. The switch itself is not an expensive unit, but it was made in Britain and not the Orient. The on/off movement seemes very solid, so I was definitely surprised when the ground interupt didnt work out. Here is my next question:
I plan to leave the switch just where it is: under the battery tray and the switch assessable from the wheel well, but I was going to spice into the small red wire that that comes off the positive battery cable and runs to the relay. I assume that spicing the cut off switch in this wire would preclude the car from starting. I realize that the heavy cable runs directly to the starter would still be energized. Is this an OK plan? I'd love to hear any other suggestions/ideas on the subject. Keep in mind that I want to keep this simple and use as little wire as possible. Thanks, George
As far as your buddy goes, "amps volts for the positive side", doesn't really hold up. If you pull the entire ground system, it will work effectively. I personally have the positive side cut off, but that is just because that is how NHRA is. I would tend to lean twords the switch itself being the culprit which is why I preferred a brand name unit. I've had mine for 2-3 years now with zero problems, I recently did a voltage drop test across the switch while cranking the engine (voltage drop test will tell you how the internals of the switch are holding up), and it was .01v. Which the acceptable limit for a power side switch is up to .05v. It's still about brand new internally.
Also consider, what is the diameter of your ground cables? Are they connected snug at the switch? Do you still have a body ground from the battery that doesn't go to the switch? (can contribute to the problem).
You mentioned before you bought a $7.50 switch, figuring I paid $40 for my Moroso....somewhere I believe there is a "get what you paid for" in that comparison. The "300a rating" you mentioned may have just been surge and it won't hold much constant. Just a guesstimate. The Moroso switch handles a 1,000a sure and 175a continuous. 'Overkill' is something that is hard to do when it comes to electrical.
Personally, I'm not sure I would run the switch listed as a switch to power the entire ground system. I am running a Moroso brand switch in my car that is rated to 175 continuous amps, and I'd trust the Moroso over a no-name brand. Just I'd imagine the contacts and internals to hold up a bit better.
