Mounting Inertia Switch when using underdash filler panel ... - FFCars.com : Factory Five Racing Discussion Forum

lynnhowlyn · 07-23-2012, 05:24 AM

OK - I'm using one of Mike Everson's Underdash Filler Panels (which is a very nice piece BTW) and am looking for a suitable place to mount the Inertia Switch.

I understand the Inertia Switch needs to be 1) mounted "upright" (e.g. with red button on top), 2) it needs to be mounted where you can get your finger on the red button to reset the switch if needed, and 3) it probably should NOT be mounted where it covers up the chassis number that's "etched" into the 2 inch tube to the left of the steering column.

But to some degree, the underdash panel restricts/limits places to mount the switch.

Extending (lengthening) the switch wiring is easy enough - so there would seem to be lots of flexibility ... so ideas (pictures) of where others have mounted their switch would be greatly appreciated.

Thanks

Lynn

Frank Messina · 07-23-2012, 05:42 AM

We used to mount them on the little step at the rear of the trunk just to the left of the trunk opening. That exact spot may be gone on the MK IV due to the lowered rear but you should still be able to make it work there. Putting it on/near the dash is pointless as it will be protected from impact in the event of a rear end collision. Mounting it where you can get your finger on the red button does not mean from the driver's seat. It needs to be in a spot where it will trip if you get whacked.

Frank

JKleiner · 07-23-2012, 11:11 AM

I looked but did not find a photo of mine Lynn. I realize that your under dash filler may restrict your options but FWIW I mounted it on the 2X2 tube that runs behind the dash because I specifically did want to be able to reach up behind the dash to reset it in the event of an off track excursion. When I mocked it up I gave the chassis round tubes a couple of good whacks with a deadblow hammer to assure that it would trip with impact. I've gone off course a few times without it tripping but earlier this season I went off with a pretty good hard bounce and it did.

Good luck,
Jeff

akpingel · 07-23-2012, 11:49 AM

I think in the RF wiring instructions there is a picture of one mounted in the trunk, even though the wires are not long enough to mount it there. I plan on extending my wires and mounting mine in the trunk somewheres.

306rangerfordguy · 07-23-2012, 01:14 PM

I agree with Frank. I have a Mark IV and mounted it inside the trunk on the left rear corner like Frank stated. It is out of the way but easy to get too. I would think it would work inside anywhere on the chassis as long as it is solidly mounted so it will trip in the event of a collision.

bmcglone · 07-23-2012, 02:03 PM

I mounted mine under the dash to the left of the steering wheel mount. I will post a picture tonight.

MPTech · 07-23-2012, 03:47 PM

Contemplating the location of my inertia switch as well.
Seems like mounting it under the dash would be better from a convenience stand-point (ie: in the case of an off-road excursion, don't need to get out of the car on a race track), but does it effect the sensitivity? Also, should it be mounted to a main frame section? the main bar running under the dash? or could it be mounted to one of the vertical 3/4" bars next to the tranny tunnel?

btw, bmcglone, received your kit end of Feb and ran it @ London Autocross last month???? WOW! you are a building machine! I get get moving on mine! Looks great!

mirose · 07-23-2012, 04:38 PM

I have the filler panel too. My inertia switch,however is incorporated into the EFI computer harness, which I have in the passenger footbox. There is about 4-6 inches of room on the 2" tube between the passenger door and the edge of the filler panel (it doesnt go from door to door) that I used to mount it. You can get your hand up there easily. I think there is a similar gap on the driver's side where the RF harness has the switch attached.

AC Bill · 07-23-2012, 04:52 PM

Easy to reach, and closer to what Ford designed for the mounting location. I'm not sure if it would be less effective in another location or not, (if in an accident)?

JKleiner · 07-23-2012, 07:28 PM

Quote:

Originally Posted by AC Bill

I'm not sure if it would be less effective in another location or not...

The inertia switch doesn't know where it is in relation to the car. It works on a sudden change of direction such as what happens upon impact. Ford, and other manufacturers, are all over the map as far as location; Fox body Mustangs had them at the rear near the taillights, later ones have them behind the dash on the driver's side, pickups and vans have them behind the passenger side kick panel, etc. The important thing is to have it mounted rigidly to a solid part of the car.

Jeff

lynnhowlyn · 07-23-2012, 11:37 PM

Quote:

Originally Posted by AC Bill

Easy to reach, and closer to what Ford designed for the mounting location. I'm not sure if it would be less effective in another location or not, (if in an accident)?

Hi Bill -
I've looked at your mounting location several times and am having a devil of a time figuring out exactly where it is .... a picture pulled back a bit for more perspective would be really helpful. Or perhaps a description of the "where" ...

I also like mirose's suggestion of mounting the intertia switch at the other end of the cockpit .... e.g. between the passenger end of the underdash panel and the passenger door. Will need to see if that might work for me also - and still leave room for the underdash 'courtesy lights' I'm planning on both sides of the cockpit.

(Sidebar: The courtesy lights I'm wanting to do will look kinda like the ones in the attached picture that was "borrowed" from someone else on the Forum (my apologies to the "borrowee" for forgetting where the picture came from so credit can be given ...).

Thanks

Lynn

rich grsc · 07-24-2012, 01:50 AM

Thats the driver side trunk panel.

Joe · 07-24-2012, 01:59 AM

Mine is at a similar location.

RGHarvey · 07-24-2012, 02:58 AM

I have the under dash panel and EFI system as well. My fuel pump relay is located above the passenger side footbox. I located the inertia switch on the cockpit side of the firewall, on the 3/4" square vertical tube where the firewall extension is fastened. I can still reach it fairly easily with the dash attached.

AC Bill · 07-24-2012, 05:57 PM

Quote:

Originally Posted by rich grsc

Thats the driver side trunk panel.

Exactly. Just up and slightly forward, of where Joe's switch is located. Using a donor harness, this general area is the best location for it.

MPTech · 07-24-2012, 06:01 PM

I have the switch, does anyone know where to find the plug? or have one they won't be using?

JKleiner · 07-24-2012, 06:40 PM

I might have one. I'll look tonight and if so it's yours.

Jeff

JKleiner · 07-24-2012, 09:33 PM

Quote:

Originally Posted by MPTech

I have the switch, does anyone know where to find the plug? or have one they won't be using?

I've got a new pigtail Mark. PM me your address and I'll drop it in the mail.

Jeff

bmcglone · 07-25-2012, 05:35 PM

Better late than never.

The switch is mounted to the 2" x 2" about an inch to the right of FFR's serial number stamp.

Brett