Handling SRS with aftermarket seats/5-point

Automotive
#1

I recently installed a new bucket & a 5-point harness, and I’m eventually going to install three more.

I’m currently trying to deal with the fact that, without the original seatbelt and possibly the seat airbag, the car disables the airbags entirely. I’d like to be able to get them back on, at least in the interim until I can replace all the seats (I have to make custom frames for the back bench being replaced to drop in two buckets).

My current thought is to find out which pins on the seat harness are for the belt sensor and make and try to match the resistance or overall current that a valid connection would have. I don’t know yet if the car is sending another signal to the airbag itself. It has a two pin connector, but if using the chassis ground one could be a sense.

It’s a 2013 Ridgeline.

Cheers,
-Jim

#2

The rule of thumb with airbags is not to fuck with your airbags. I especially wouldn’t be trying bypass any built in system by trying to match resistance.

I’d buckle in a seatbelt to the OEM receiver, and pull the “seat airbag” out and put it behind the passenger seat or something, still connected.

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#3

There is also the pax seat sensor that tells if someone in seat or not.

Defintely agree air bags are not something to play with.

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#4

This still involves shenanigans with the wiring harness for both of these, as the original seat is removed. I might be able to yank enough of it out to leave the buckle underneath the seat if I can secure it well enough.

Right now at worst if I screw up that sensor, SRS system disables itself which is currently what happens regardless.

#5

If the vehicle is equipped with a seat sensor, I don’t see why you couldn’t replicate that into the new seat.

#6

Applies at least for the passenger side, which I currently at least don’t have to deal with until I install the next three seats.

The basic guidance I had been given in the past is a 3.3 Ohm resistor where the sensor wiring was present for the seat belt and not do much else, however that guidance was a while ago and I am not sure if there was a better method.

However, I may reinstall the factory seat in the front and just use the buckets for the rear which will make part of this moot, but I am evaluating all options still hence why I haven’t just replaced every seat yet nor taken this up to speed whilst I evaluate. The bench seat there doesn’t have airbags nor sensors of its own and breaks constantly anyway. The biggest hindrance to keeping the 5 point with the factory seat is that there are a decent amount of electronics to it internally, and it would have to be reworked a bit to get the anti-submarine strap in the proper position.

#7

You sure about that? I’ve been inside airbag control modules for the older Miatas and will tell you those have suicide parts inside: A coil of nichrome wire and heat resistant tape is wrapped around a thermal fuse and connected to a transistor. If there are errors with the airbag system and they go unfixed for too long, the airbag control computer in that car will kill itself.

Wouldn’t surprise me to see that in other types of vehicles too. Those modules in the Miatas were made by Ford.

#8

And you better use a flameproof / metal film resistor. A carbon film one will flame out and a flame around foam and other seat materials would be the last thing you want in a crash.

#9

I’m talking about the seatbelt sensor

The airbags in this vehicle should fire with a missing bag, but not without the sensor because it thinks the occupant is unrestrained.

#10

If the airbag is pulled the airbag computer will know. It needs to be replaced with a resistor and that better be a flameproof or metal film type resistor.

#11

I’m not denying the computer knows, but it the SRS system isn’t completely disabled when the seatbelt is considered in place versus the airbag, in which a warning light comes on but the system is still otherwise operational.

Regardless, I’m evaluating all options for it and will likely do both, the seatbelt is the first one though.

#12

Recaro used to make a resistor that sold with their seats that replaced the OE seats that came with airbags. I don’t know if they will sell them separate or if they ever became available in the US.
There also used to be an aftermartket(Japanese brand, iirc) steering wheel company that sold steering wheels that came with a 2K ohm resistor that did the same. It was a chunky resistor that was about 3/8" square & perhaps 2" long. I don’t recall the watt rating on it or if it was sold in the US either.
A number of side airbags aren’t available alone with the airbag and come with the seat back, occupant sensors are also the same and often either come with the seat frame of the bottom cushion.

Sounds like the Ridgeline is going to have fun doing serious off roading. :slight_smile:

P.S. re harnessbelts & OE seats. Most OE seats(that have a tubular frame) aren’t rated to take harness belts that have the shoulder harness mounts attached to the floor as there is risk of the seat frame collapsing that will result in spinal injury according the Schroth. IIRC(but you need to check again), mounting them on a harness bar behind the seat doesn’t seem to carry the same cautionary warning.

#13

You are correct. You have the have the shoulder harness bar in the correct position or it will compress your spine. There are rules of thumb out there on the right height to mount them. He apparently gets more serious than what I did in my Jeep off-roading. I still have my stock seats & seat belts. I’ve almost dumped it on its side, I’ve raced it several times in a hill climb challenge. The Jeep has scars to prove it lol. Both B pillars are no longer the same shape as they are supposed to be. I had fun times & can tell you exactly how & why each of the sheet metal scars are there.

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#14

Ranch Use; the factory harnesses don’t retain people safely under those conditions (someone’s already slipped it and hit their head during some pest control). Eventually planning a Score competition in it (ridgelines are funny in it, but they have competed even if just in their own little group), but this is the more immediate need.

Yup; Right now it’s a tad high on the shoulder (used some extensions from the B Pillar up high originally for grips), but a new harness bar just for the purposes should arrive via FedEx today if all goes well. It will cross both B pillars behind both front seats. When the back seats are done will make use of the original child anchor locations since they’re nice and sturdy at about the right height.

It’s not just the OE seats though, even proper seats are not designed for the harness to go to the floor; SPI ratings and 4/5/6 point harness designs are only supposed to be anchored +/- 5 degrees relative to the tangent formed at the top of the shoulder. Doesn’t matter what seat, it’s just a physics thing. Harnesses are generally supposed to go to a roll cage bar or similar anyway. I am still planning the roll cage.

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#15

This makes me giggle like a 5 y.o. & makes me think of the of fun times. :smiley:

#16

Well I just got the harness bar and will be in the space this evening. I’m going to try and dissect the factory seat and see if I can’t safely get the antisubmarine strap through it and nullify the entire need to deal with the airbags

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