Battery cable switch location..

iwantacobra427 · #1 (**permalink**) 04-20-2008, 11:48 AM

What do you guys think of my proposed battery cable switch location?
-John

ERA Chas · #2 (**permalink**) 04-20-2008, 02:52 PM

You'll have to remove it to change pads or bleed that caliper.

iwantacobra427 · #3 (**permalink**) 04-20-2008, 03:34 PM

That's a good point.. I could move it to the left but there's less clearance with the rear suspension. The switch posts would be about 1/4" from a rear suspension cross bar. I guess that's ok if the that bar doesn't move forward toward the passenger compartment? Or I could cut off about 1/8" or 1/4" inch of the post ends to increase the clearance?

Bill Bess · #4 (**permalink**) 04-20-2008, 04:56 PM

John, looks good to me, I can't really tell how close it is to other things that might be in conflict.

I feel its most important to locate the master switch where you can easily close it from the drivers seated position, along with having the fire extingusher located so you can also reach it in the same manner. If your in some sort of emergency situation, easy access is critical.

Plan for safety, Best Regards, Bill

iwantacobra427 · #5 (**permalink**) 04-20-2008, 09:11 PM

Bill:
I won't be racing so the battery switch will be behind the passenger seat. I'm using it for security and when the car is sitting for several months. The seats are on tracks so it shouldn't be difficult to access.

Pete Munroe · #6 (**permalink**) 04-20-2008, 11:18 PM

John,

Seems like you are doing this the hard way.

Why do you want to mount the battery behind the seat? Access?

To mount the battery in the right-rear fender...ERA supplies the battery tray, the hold down bracket, and builds holes in the chassis to pass the battery cable though. (All came with my kit 10 years ago...maybe they don't anymore).

Battery access is NOT an issue...if you are using a modern battery like the Optima? or Exide "Select" sealed "gell-cells?", there is no need/way to add water anyway...very little corrosion as there is no acid leaking out, so terminals may oxidize over time but they don't get nasty and need to be cleaned very often.

Charge it by connecting the charger to the battery side of the solenoid on the firewall...the chargers negative clamp I put on a bell-housing bolt.

Even with little use, the newer batteries hold a charge well...lead-acid can hold a high percentage of charge for a month.

Use the firewall mounted solenoid...you can run a second solenoid on the starter also, but the firewall mounted solenoid looks stock and provides access to the battery.

My old, circa 1998, ERA 289 FIA manual, pp 54, shows the cutoff-switch on the bulkhead about 6 inches over an up from the px side of the car. WAY to the right of where you are looking to mount it.

The bulkhead mounting is solid, the switch isn't close to anything that could move and short it out. I insulated the terminals anyway.

In that position it will not interfere with removing the access panel for brake bleeding or pad replacement.

I am thinking about adding a SECOND switch in series on the dashboard like Peter Portante's bronze "russhsn" FIA race car has...much easier access in an emergency, although I suppose the "sanctioned" race groups want the switch external on the body...I do not want to cut a hole in the body, but may put one on the dashboard.

As it is, behind the seat, it's a sort of "stealth" cut-off when I park the car!

A friend has an early 63?/64? AC Cobra and the battery is behind the passenger seat...original position!...also...original battery acid-holes...in the original carpet.

I think that is called "patina"...sweet. He will never change those 45 year old acid eaten carpets!

Have fun, call ERA, talk to Doug or Bob before you get too innovative with rerouting 600+ CC amps.

Pete

Pete Munroe · #7 (**permalink**) 04-21-2008, 12:05 AM

John,

Well, nothing like rereading the original post...! Ooops.

OK, you were NOT going to put the battery behind the seats, but only the cutoff switch.

OK, why have you decided on not using the position ERA shows in the manual?

Seems the ERA recommended location is the way to go...solid, stable location on a fixed bulkhead. No interference with anything involving the removable panel, pad replacement or bleeding the brakes.

If you are concerned about shorting anything out, make boots to cover the terminal/cable ends.

Sorry for not reading carefully, was fixated on my friends original 289 AC car with battery behind the seats.

Pete

iwantacobra427 · #8 (**permalink**) 04-21-2008, 05:19 PM

Pete:
No problem! I guess I need to take another look at it.. It just seemed very tough to get access to that area. The rear end is already installed. I think what holds the switch in place is the large thin nut and star washer. So I thought it was supposed to be attached to sheet metal. I don't think it's designed to be attached to a solid square frame member. How would I attach it?

SSSammy · #9 (**permalink**) 04-21-2008, 05:38 PM

John, I don't know FIA's, but just FWIW, I have this pic of where ERA mounts the 427 series switch when you buy the rear battery .. see the upper right of the photo .. carpet added by me:

Sam

Pete Munroe · #10 (**permalink**) 04-21-2008, 10:03 PM

John,

I have not had much luck posting photos to the blog side, hard to make them small enough and still be usable, but have had more success posting on the gallery side. Will try to get some shots of the switch from both sides. May take a few days to get under the car.

I would guess I did the wiring before the rear went in. But can not remember.

There is enough room to put the switch and cables in the recommended position, and of course a picture would help.

When in doubt call ERA...Doug has been in the shop since at least 1997, he is sharp and lots of help for most everything...he has to make things work on the cars that are the "turn keys", so he has to be able to do it.

Again, will try to post some photos...my ZIP drive died and the 100's of pictures of the cars' assembly are frozen on unreadable Zip discs...

Pete

snakebitekit · #11 (**permalink**) 04-22-2008, 11:56 PM

This is so timely for me. I am having a difficult time trying to figure out the track for the wire from the battery to the cut off switch. I installed the rear before the cable thinking that if I ever needed to to change it out I should not have to remove the rear end. Now I am having a problem trying figure out how to run the cable. ut ohhh did I screw up?

Dennis

cobrajeff · #12 (**permalink**) 04-23-2008, 06:09 AM

Here is where I mounted the switch in my ERA FIA - I can reach and activate it, even while buckled up:

Here is how it looks from the backside:

regards,

Jeff

Bill Bess · #13 (**permalink**) 04-23-2008, 07:08 AM

Jeff, Perfect location for access and safety.

For security its easy to mount a cut-off switch in a hidden location so they still can't start it and drive it off. Anyway most of the time the beast is under lock and key in the garage.

Bill

iwantacobra427 · #14 (**permalink**) 04-23-2008, 06:27 PM

Quote:

Originally Posted by snakebitekit

This is so timely for me. I am having a difficult time trying to figure out the track for the wire from the battery to the cut off switch. I installed the rear before the cable thinking that if I ever needed to to change it out I should not have to remove the rear end. Now I am having a problem trying figure out how to run the cable. ut ohhh did I screw up?

Dennis

positive cable through the rear end frame. Use a flashlight and feel around for the hole in the rear frame..

Pete Munroe · #15 (**permalink**) 04-23-2008, 08:42 PM

John,

I jacked up the rear of the car but can't get any pictures in focus without removing the wheel. Have to do an "annual" on the car soon, when its up on stands wheels off I will try to get some pictures and post them at the CC portfolio...probably too late to help you.

Jeff's 289" FIA switch location is ideal, easy to reach...but I think Jeff's FIA 289 gas tank is a racing fuel cell mounted low in the 427" position. That leaves the vertical bulkhead wide open. The 289" FIA car normal gas tank is vertical and pretty much blocks using the rear bulkhead.

Looking at the switch location from behind the rear wheel, it is outside of the rear end cradle.

The location the ERA manual shows works quite well...call them if you think you need to.

I either use shrink tubing or rubber "terminal boots" I got found at Aircraft Spruce and Specialty on any of the exposed terminal ends to prevent shorts.

The cable I used is actually #1 gauge copper cable. Came in a kit I got from Jegs or Summit.

I sleeved most of the cable with clear tygon to keep the insulation from wearing through at any of the chassis contact/through points...that was a PITHA, but no worries...

iwantacobra427 · #16 (**permalink**) 04-25-2008, 05:20 PM

Pete:
I spoke to Doug today... The manual has it right.. It's tough to see where it mounts but he said the measurements are right on.. so it does put it right behind the passenger seat but to the left of where my pictures show. Thanks for your help!

Pete Munroe · #17 (**permalink**) 04-25-2008, 06:02 PM

John,

Doug not only knows about every thing you need to know to finish one these cars...he's very patient about explaining it!

This weekend I will be working on the car, will try to post a photo of the switch from the wheel well side...should be able to show proximity of the switch to the rear end cradle.

Pete

Pete Munroe · #18 (**permalink**) 05-03-2008, 08:05 PM

John,

Finally got a picture of the switch in place.

The boots are homemade out of some stock plug covers/rubber tubing I had lying around.
Anything that can be shorted out WILL be shorted out. I try to cover anything with 600+ amps with insulation.

Yea, it looks tight...hence I used the boots, but it fits.

I found boots from Aircraft Spruce and Specialty for the starter solenoid, but couldn't find anything a couple of years ago when I was doing the switch.

Am considering adding another cut-off switch to the dash board for safety reasons.

Go to the ERA site and you can see that Peter Portantes "Rushin" bronze 289 race-car has the dash mounted cut-off.

Doubt any corner-worker would know where to look for a "behind the passenger seat" cutoff in an emergency. I can hardly reach it with a bum shoulder.

(Does anyone know how to post attachments larger than 39 KB? I keep SEEING posts with attachments that are ~80kb or greater. IN THIS THREAD ALONE ARE 3+ huge and useful attachments...HOW DO YOU GUYS DO IT? I get always get photos over 39KB kicked out. These little tiny 39, or less, KB's post are almost useless.

Another thread...for another time.

Pete

iwantacobra427 · #19 (**permalink**) 05-10-2008, 05:41 PM

Thanks Pete! Yeah I'm going to cover the posts too. I was going to use car battery covers but I think I have some spark plug boots/covers laying around here somewhere..

lamaluv · #20 (**permalink**) 05-10-2008, 09:42 PM

I mounted my battery cut off switch on a metal plate that is on the support tubes that run from the under the dash to the floor boards. It is easy to reach while belted in and accessible from outside of the car for track use. Even if you don't ever intend to track your car, having the switch handy is important. If you ever have a your wiring short out and start to smoke you will be glad to have the battery cut off where you can reach it quickly. For security when the car is parked I just remove the red key that is the cut off switch and take it with me.

Dick