Cut Off Switch Question

[PNWTim]

I am new to this forum but have spent several years on the Camaros.net forum as well as a couple Triumph forums. I say this because I am curious regarding the penchant for installing cutoff switches in the FF5 builds. I am mostly focused on Cobras and Coupes and see them installed regularly. This is not a common practice in Gen 1 Camaros (I have a 69) unless a car is regularly tracked and it's required by the sanctioning body, so I am really curious as to why it is so popular on these cars.

I am not making a judgement call at all - just trying to figure out the rationale. I am accustomed to the concept that most cars like ours are stolen with flat bed tow trucks so alarms, cutouts, immobility devices, etc. are not really deterrents to determined thieves. Again, just curious, not debating the merits.

[Its Bruce]

Infrequent driving and subsequent storage, especially with EFI systems that will always have some small amount of current draw.

[edwardb]

For non-tracked cars where sanction rules aren't in play, I agree they aren't required and certainly optional. However, I have chosen to install one in all of my builds. Partly for security, but for the reasons you mention probably not very effective and wouldn't be the only reason for me. Mine are there mainly for ease of maintenance, e.g. I can disconnect battery power without removing cables from the battery. Which can be a little difficult to access in some builds. Plus I like having the power shut off during the Michigan winter hibernation. Ford Performance instructions for the Coyote control pack specify it to be powered at all times to save certain learned tuning, e.g. fuel trims, error codes, etc. So I power that from the hot side of the switch. The current drain is extremely low and doesn't seem to drain the battery during storage.

[PNWTim]

For non-tracked cars where sanction rules aren't in play, I agree they aren't required and certainly optional. However, I have chosen to install one in all of my builds. Partly for security, but for the reasons you mention probably not very effective and wouldn't be the only reason for me. Mine are there mainly for ease of maintenance, e.g. I can disconnect battery power without removing cables from the battery. Which can be a little difficult to access in some builds. Plus I like having the power shut off during the Michigan winter hibernation. Ford Performance instructions for the Coyote control pack specify it to be powered at all times to save certain learned tuning, e.g. fuel trims, error codes, etc. So I power that from the hot side of the switch. The current drain is extremely low and doesn't seem to drain the battery during storage.

OK, that makes sense. I was wondering, particularly with PCM builds, why you would want to cut off the computer and lose it's memory. Battery location and isolation are not something I normally think about since my experience is with OEM and even with the battery in the trunk there is easy access. I have also seen some builds where remote posts are installed for tenders or a jump if necessary.

[RogerRoger88]

For non-tracked cars where sanction rules aren't in play, I agree they aren't required and certainly optional. However, I have chosen to install one in all of my builds. Partly for security, but for the reasons you mention probably not very effective and wouldn't be the only reason for me. Mine are there mainly for ease of maintenance, e.g. I can disconnect battery power without removing cables from the battery. Which can be a little difficult to access in some builds. Plus I like having the power shut off during the Michigan winter hibernation. Ford Performance instructions for the Coyote control pack specify it to be powered at all times to save certain learned tuning, e.g. fuel trims, error codes, etc. So I power that from the hot side of the switch. The current drain is extremely low and doesn't seem to drain the battery during storage.

Hi Paul, which switch do you use? I'm assuming it's removable.

Thanks,
Jesse

[edwardb]

Hi Paul, which switch do you use? I'm assuming it's removable.

Thanks,
Jesse

I've used the Ron Francis MS-1 on several builds. Very robust mechanically and electrically. If by "removable" you mean does it have a "key" that's removed, no it doesn't. Those that I've seen aren't nearly as solidly built IMO. Plus, as indicated in my response, I don't consider security to be a major factor. Having said that, I mounted the disconnect on my Coupe under the dash where it's not easily noticed.

[RogerRoger88]

I've used the Ron Francis MS-1 on several builds. Very robust mechanically and electrically. If by "removable" you mean does it have a "key" that's removed, no it doesn't. Those that I've seen aren't nearly as solidly built IMO. Plus, as indicated in my response, I don't consider security to be a major factor. Having said that, I mounted the disconnect on my Coupe under the dash where it's not easily noticed.

Thanks for the info!

[F500guy]

I used this one so it has a removable key and ignition cut out as well. Not in proper place for track sanctioning bodies, but will keep "honest" people from joy riding, can be operated with the car running and I have already used while working on some lighting (after blowing a couple fuses first-slow learner)! Just a note, It is a good idea to have the alternator output and battery tied together so if it gets used while running it will not damage the alternator.

Cutoff Switch.jpg

[PNWTim]

I used this one so it has a removable key and ignition cut out as well. Not in proper place for track sanctioning bodies, but will keep "honest" people from joy riding, can be operated with the car running and I have already used while working on some lighting (after blowing a couple fuses first-slow learner)! Just a note, It is a good idea to have the alternator output and battery tied together so if it gets used while running it will not damage the alternator.

Cutoff Switch.jpg

Thanks for the link and info. There are pretty compelling arguments in favor so I will probably do the same. My kit completion date was advance by 10 days so I suspect I am going to have something in my garage withing the next month or so (depends on Stewart).

Interesting that you sent a link to Pegasus - that place is a candy store for all things going fast.

[DanQ]

After reading this thread, it made me wonder if I did the right thing last week when I stored my '33 hot rod for the winter. I have a battery cut-off switch mounted directly on the negative terminal. I figured if there was ever a time wiring began to smoke or the starter stuck on, it would sure be nice to be able to kill all electrical power in a few seconds. Luckily that issue has never happened. When I stored this car, I flipped the switch open (power off) to prevent any electrical fire just in case a rodent decided to chew into my wiring and also to prevent parasitic electrical loss from sitting unused for such a long time. I am now concerned if my computer will be affected by having no power to the ECM for the next 5+ months of storage. I do place a float charger on the battery a few times when we are up there during the winter months to keep the battery 100%. Maybe I should flip my disconnect on for those few hours to keep the ECM "alive". I am running a 5.3 LS motor and am using the OEM PCM.
Image - 2023-12-02T165837.979.jpegImage - 2024-03-06T133252.058.jpeg

[Its Bruce]

It'll reset your fuel trims but not the tune. If your tune is good, it won't be an issue. If your tune is not good, simple driving for a while will reestablish the short and long trims.