View Full Version : Inertia Switch Question
BrewCityCobra
06-10-2022, 10:21 PM
So a quick question on the inertia switch - and more specifically the inertia switch connector.
Does anybody know if there is a way to add a pin/wire to the center position (see below)? I'm assuming it is a separate crimped part (like a Weather Pack Connector) that can be added separately I just wasn't aware of the style/company/where to purchase. If not, is the connector sold somewhere as a pigtail?
167957
I ask because I was hoping to use that pin location to power an indicator light. It is my understanding that the right pin is the Normally Closed pin (e.g., attached to the fuel pump) while the center is the Normally open pin. Since I'm running a one-wire alternator I can't do an alternator light by the key I thought I could possibly use the red LED above the key for an "inertia switch tripped light." The idea being that should be inertia switch be tripped for some reason that the red LED above the key would come on and inform the driver who can then reset the switch.
rich grsc
06-11-2022, 06:42 AM
You don't need a light to tell you the inertia switch is tripped, the engine quits
Would this do it?
https://www.amazon.com/Connector-3-way-Inertia-Switch-WPT-414/dp/B07JBP98X6
Edit: Never mind. You're just looking for the pin itself, right?
JohnnyB
06-11-2022, 03:36 PM
Connector Experts (https://connectorexperts.com/)probably has the terminals if you can figure out what you need but they are pricey. It might be better to splice in a pigtail like RJD suggested. Looks like this one might work https://www.amazon.com/Connector-3-way-Inertia-Switch-WPT-414/dp/B07J5RDT5N.
BrewCityCobra
06-11-2022, 05:51 PM
You don't need a light to tell you the inertia switch is tripped, the engine quits
I mean, not immediately right? The inertia switch just kills the fuel pump so the engine would continue to run so long as fuel remains in the bowls of the carb (I may be mistaken). While I did make a point to mount the inertia switch in a location the driver could reach if need be, I don't really expect to reset it before the engine kills.
In the end, this would just be a niceity - certainly not a game changer but just a way to incorporate a usable LED in the "alternator indicator" position since an alternator light proper isn't easily doable.
BrewCityCobra
06-11-2022, 05:55 PM
Connector Experts (https://connectorexperts.com/)probably has the terminals if you can figure out what you need but they are pricey. It might be better to splice in a pigtail like RJD suggested. Looks like this one might work https://www.amazon.com/Connector-3-way-Inertia-Switch-WPT-414/dp/B07J5RDT5N.
Agreed, I wasn't sure how/what they would sell but I think the spliced-in pigtail is the way to go. I think your link is the ticket! Thanks!
BrewCityCobra
06-11-2022, 05:55 PM
Would this do it?
https://www.amazon.com/Connector-3-way-Inertia-Switch-WPT-414/dp/B07JBP98X6
Edit: Never mind. You're just looking for the pin itself, right?
I think your link was the right idea, just needed the female version. Thanks!
edwardb
06-12-2022, 07:10 AM
FWIW -- I've driven thousands of miles with multiple builds that included the inertia switch. It has never tripped, e.g. opened up requiring a reset. Yes, I've heard a couple anecdotal reports where a heavy bump or whatever supposedly caused it to trip. But hasn't been my experience at all. It's there in case of an accident or rollover. In that case an indicator light is the least of your worries. An indicator is technically possible for sure but of little/no value IMO. I'm betting you'd never see it light.
Norm B
06-12-2022, 07:47 PM
I don't have the FFR supplied wiring harness (not allowed in Canada because it is much safer to cobble something together yourself than import one from the US) but, I thought the inertia switch was on the ground side of the fuel pump circuit.
On my build the red light was repurposed as a brake warning light. It comes on if the park brake is on or the brake fluid is low.
Norm
Hoooper
06-13-2022, 09:45 AM
The inertia switch trips if you crash, it takes a 10+ g impact to set it off. Thats higher than the impact needed for most airbags to go off, its not going to trip just driving around. Youll know it tripped because youre in the wall, no need for a light.
BrewCityCobra
06-13-2022, 12:50 PM
Really appreciate all the input here - extremely helpful. Not sure why I had it in my head that there was a chance an accidental (e.g., non-crash related) trip could occur on the track but it appears no such issue appears to reasonably exist. So as much as I love LEDs and messing with the dash - this seems like a project that would just be a complication for complication's sake and probably not worth it.