darguy

Hey Gang

I'm putting an OMP kill switch in my 99 FRC (while the cage is going in). Looking at the schematic - it's a little vague. Before I blaze a trail, I thought I'd ask for directions, so to speak.

Anyone know specifically which circuit to tap into for the 'coil' and 'ignition' on a 99 C5?



Thanks in advance!

redtopz

Rule #1: never look at a schematic or read the instructions. Too confusing .

All I did was get my wire cutters and cut the lead going to the alternator and the main power line to the battery. Extend each lead through the firewall to the disconnect switch and then back to the other side of the lead. Done. My disconnect switch has 4 poles (2 for battery and 2 for alternator). If you don't do the alternator then the car will continue to run with the switch turned off.

sperkins

http://forums.corvetteforum.com/auto...lp-needed.html

See post #7. Ask Tim to send you the pics since they're not posted any more.

trackboss

I've always been confused with the switches that have the additional small poles. I use the two pole type. Pole "A" I connect the battery positive and the alternator wire. Pole "B" I connect the wire going to power the car. When I cut the switch the alternator is essentially sending power to the battery and because the switch is off no power from the alternator can be sent anywhere else so the car shuts off. The multi pole setup in the diagram above may be a better way, but I have never had a good explanation of it so I do it my way and it has always worked on multiple cars.

Jason

This.

travisnd

Just cut into the smaller wire off the positive battery lead. It'll kill power to the main distribution block and turn the entire car off. No need for one to the battery and another to the alternator like in other cars.

See Tim's post

C4B4the04

After really mulling this over, I think Tim's way is best. If you don't have a starter load on the wire, you can install a fuse (150 amp would work, like the kind for car audio) just in case it shorts out. You minimize power drop by having 17 extra feet of cable on the starting system (so you can use that Harley battery instead of a big old group 78 in there).

I recognize this doesn't work for every car but cutting into that distribution wire really is the best solution. Technically, it is not a true disconnect; in the event of a front side collision, you still have a hot wire to the starter. I don't know if that is ok for club rules?

Cassidy

redtopz

Rule #2: Never listen to my advice

I guess with my short attention span I forgot to go back and take Tim's advice. Making notes to do so now...

travisnd

The way you did it is the "normal" way to do it, but on these cars you can get away with just cutting the one wire.

darguy

Thanks for the input, I've PM'd Tim as suggested.

I'd thought that there must be a clever way to disable everything...

My initial thoughts had been that wiring the A4/C3 Batt+ (hot at all times) feed to the BCM through the kill switch might take care of shutting down the BCM (or perhaps the A2/C3 ground at the BCM). Figuring that would shut the car down. And, something similar to kill the coil function if necessary.

I agree, killing all power to the distribution block is a good 'nuke them from orbit' kind of approach, and easy to sell during Tech inspection compared to a circuit analysis for why the system is disabled. Guess I didn't need a 4-pole switch...

lefrog

As Tim's info is not available anymore, I made a video of my install: