BATTERY CUTOFF SWITCH C1

[JOHN ARAUJO]

Hello,
I'm a new member of NCRS and recently bought my first 62 Corvette. I have started going through the electrical system and noticed a slight draw on the battery. I have seen in Driveline adds for battery cutoff switch which would cure the problem. My question is, what is the best type of switch for this application, a knife switch or rotary knob switch. Also is this a common problem for C1 Corvettes and should I be looking to find where the draw is coming from. Thanks, this will probably be the first of many postings from me.

[Rob Edwards]

Re: BATTERY CUTOFF SWITCH C1

John-

Having enthusiastically purchased a knob cutoff switch for our '62 last year, imagine my surprise when, after installing it and removing the green knob (completely!) to discover the clock still working, the lights still operating, etc. So I guess my vote would be a blade type switch. Of course, others will have had good luck with the knob. Also a consideration is that the spring ring battery cables on a '62 may not snug down tight enough on the cutoff switch terminal, though I can't speak from experience on that (I put on spring ring cables last fall....)
I guess the other comment you'll get is that the draw you have isn't normal and that merely putting in a cutoff switch isn't the 'correct' solution, finding and fixing the wiring problem is. You'll read lots of horror stories in the archives of C1's burning to the ground because of wiring issues and a general lack of fuses. They scared me enough to replace our Bubba-ized spaghetti-splice collection with a new Lectric Limited dash harness last winter. You may also want to search for posts on fusible links, which are another good protective device, if not exactly original or correct.

[Brian W.]

Re: BATTERY CUTOFF SWITCH C1

Hi John:
I use the screw type battery cut off on my 62 & so far it's been good. Could the draw be the clock?

[Jim D.]

Re: BATTERY CUTOFF SWITCH C1

I replaced every wire in my car and use the "knob" style disconnect. I have no electrical problems whatsoever. These cars are 40+ years old. I can't imagine keeping the original wiring. Seems like that's just asking for trouble.

[don 42616]

Re: BATTERY CUTOFF SWITCH C1

I also use knob cutoff on my C2s. 3 months ago I was at a traffic light & smoke billowed out from under my 67 hood. Horn relay wires were the cause. My cutoff saved my car. New engine loom now. Don

[Dick G.]

Re: BATTERY CUTOFF SWITCH C1

25 plus years in the Electricl field I strongly believe in what we call a Visible Disconnect. I too tried the knob style on my 57 8 years ago since at that time I could not locate a knife switch type available. For any of my future cars 60 nd 65 I will use a knife switch type. Maybe, NCRS should stress the use of the knife switch over the knob as an acceptable disconnect? At Carlisle I saw Chinese manufactured knob switches by the bucket loads on vendor tables for sale. Beware! Dick Gutman

[Rob M.]

Re: Extra fuses

Adding an in wire fuse in the clock and fuel sender unit wiring, even if you buy a brand new wiring harness, isn't a bad idea at all since these two circuits are unprotected by a fuse on the fuse block. Some people also add a fuse in the main wire (from the battery to the ignition switch (appr. 30 Amps) to protect the complete harness.

greetings,
Rob.

[Terry M.]

Re: BATTERY CUTOFF SWITCH C1

There have been threads on this board in which folks spoke to high resistance issues with the green knob style battery disconnects, even the ones made in this country. Either style is acceptable for the bonus points in judging. My experience in the electrical field makes me partial to the knife blade switch as well. I've had one on my Corvette for longer than NCRS has awarded bonus points for them. Never a problem, however, 1969s with side terminal batteries will have clearance issues with either style disconnect. I don't have an answer for that one.

[Mike M.]

Re: BATTERY CUTOFF SWITCH C1

I was at a chapter meet when a 63 Z06 almost caught on fire under the dash using the green knob disconnect. On the opps check smoke started coming out from under the dash. They needed a pair of pliers to get it disconnected. No damage. I had the knife blade disconnect then and made up my mind to only use that style after I saw that.
Mike

[Brian M.]

Re: BATTERY CUTOFF SWITCH C1

I replaced the Green Knob with the Knife style years ago.

[Mark #28455]

"needed pliers to disconnect it"

Do you think somebody missed the point and OVERTIGHTENED it! I've used the knob type on my big blocks and never had a bit of trouble. Honestly, single anecdotal events cannot be used to judge an item as there is selection bias. To accurately decide, you would need to study ALL the disconnects that show up at NCRS events over the next year or two and collect info from ALL the users.
Mark

[Mike E.]

Re: "needed pliers to disconnect it"

A plus for the green knob type that's not yet been mentioned--for parking security, you can remove the knob and take it with you--can't do that with the blade type. I drive my white 62 fuelie every day that rain is not forecast during the summer, and when running errands and parking in different areas of the city, I appreciate the knob removal feature. That said, I have had two times where, when I had not removed it, I had to loosen and then retighten the knob, because there was no continuity when I went to start the car.

[Mike M.]

Re: "needed pliers to disconnect it"

That was the problem the knob had to really tight to get continuity. The knife type make great contact and don't get hot and over heat. I've seen the green knob type hot to touch. I've never heard of any problems with the knife type, but I've heard a lot of problems with the green knob type not making good contact ect. Mike

[Tim G.]

Re: "needed pliers to disconnect it"

The most recent knob switch that I purchased has been sporadic about disconnecting. On a number of occasions I've come out and opened the door of my car only to have the courtesy lights illuminate when I thought the knob was rotated enough to disconnect power. It has gotten to the point where I rotate it two or three complete turns and open the door to check for power.

[JOHN ARAUJO]

Re: Battery switch

Thanks to all that sent a post to my question. This was my first post and I'm amazed at the amount of valuable information I received in a short period of time. The NCRS membership is certainly paying for itself.
Thanks again

John #43736