fisherbody86

If somebody would be so kind as to help me out, here's what I need. I need the resistance of the air bag and clockspring, as measured at the yellow 2 pin connector under the knee bolster at the base of the column. Basically, the resistance of everything airbag related in the column itself. I thank you in advance for your help.

Vader

I would advise strongly against testing air bag inflator resistance with an ohmmeter. You can test the CIRCUIT resistance as long as the inflator is disconnected, but not the inflator itself. Circuit resistance from the horn sounder/closckspring to the base of the column should be zero.

Or, have you already blown your bag?

fisherbody86

I have to disagree. With the connector unplugged at the base of the column, testing the inflator/clockspring with an Ohm meter is totally fine. Nothing is going to go off, don't worry about that.

Exactly, thats what I needed, the total resistance of the circut inside of steering column.
This is not what I was looking for. I need the resistance of the inflator also. I already measured it on a different car. And with the air bag plugged into the clockspring, the resistance at the connector at the base of the column is 3 Ohms. This is the total resistance I needed to duplicate to fool the air bag module into thinking that the air bag was still intact after I swapped in my Grant steering wheel.

I already installed my resistor module and the air bag light is now off. Worked like gangbusters!

Green89IROC305

i dont know why you went through all that you could have just pulled the inflatable restraint light or the module itself.

fisherbody86

For the last time, BECAUSE PULLING THE BULB IS HACK. If your check engine comes on, do you just pull that bulb too? No, you fix it!

And it wasn't hard anyway. I didn't have to go through "all that".

Vader

I still maintain that you do not want to apply any current (even the small current from a high impedance ohmmeter) to an air bag inflator. That's probably why there is no specification for resistance checks. But, if you feel that disconnecting it at the base of the column disables the inflator, go for it. Try a Simpson 260 analog meter on the Rx1 scale and see what happens. You should get infinite resistance once your ears stop ringing.

87IROCZ350TPI

From what I understand, the inflator itself can be triggered even if disconnected. There are even warnings against placing the inflator face-down on a surface citing the possability of accidental inflation. If someone is going to take the chance and test this thing, make sure it is face up so the assembly doesn't get launched at you.

Abird4u2nv1

iTrader: (-1)

As a mechanic, I have to say do not, repeat DO NOT do that. Not saying that the bag will blow, but if it does your gonna be in either a world of hurt, or your wallet will be. Youdon't want that thing blowing up at you.

87IROCZ350TPI

Green89IROC305

ditto here

CAMARO45801

ive been a ford motor master technician for 13 years measuring the are bag systems resistance along with the air bag hooked up is the only way to check total resistance and that resistance is checked constantly by the air bag module if it goes high the light goes on and sets a code same with going low thats how it works there is a miniature "ohm meter per say " in the module that checks it all the time and it doesnt blow
were some of u guys get the feeling in your head that u know more than u do i dont know but u are totally ignorant to the workings of the system and ought to not talk about it anymore till u learn more
anyways i have a 92 ill check it for u
ill be sure not to blow my air bag by testing it properly
with an ohmmeter

Green89IROC305

its not that i think i know more than i do its that i have respect for what is basicly a bomb that is in the car. its the same way with batteries for me i dontplay around with them. i do know that it takes as little as 1.5 volts to deploy an air bag and that it is possible for a multimeter to add voltage to a circuit if its a cheapo one.

87IROCZ350TPI

Edited by Jim85IROC:

Flaming is NOT tolerated on this forum. Consider this a warning.

fisherbody86

Dude, not cool. That guy is not me, I dont know who he is. How could you accuse me of being that childish. Not cool. I'll be sure to report your post.

Anyway, back to the discussion at hand. The air bag module monitors the air bag inflator by sending out a very small voltage into the inflator circut. It then measures the amperage required for the voltage to return, and calculates the resistance of the air bag with that information. It's called circut integrity. ECM's do this all the time, with nearly every sensor. That's how the air bag module, or an ECM, knows when something's unplugged. Circut integrity.

That is also the same way that a DVOM works. It too sends out a small voltage in order to compute the resistance of a given circut. It's no different that what the air bag module does every time the key is cycled "on", but you don't see anyone telling you "dude, don't start your car because the air bag might blow." If you want, I can bring in the GM air bag trouble code diagnostic charts that I got off Alldata that say exactly what I have just typed.

Vader

Since you've already done some reasearch, you'll know that you really don't want to use anything but a very high impedance ohmmeter, and only on a relatively high resistance scale. The shunt/comparator circuit in a BCM or older SIR module has a current limit, so it cannot deliver enough current to start the inflator fuse. Many ohmmeters CAN deliver adequate current.

Not knowing your skill level, your understanding of the system, and what meter you might use or how you might use it, I couldn't advise a resistance test on the inflator circuit.

I certainly cannot agree with asking someone else to go and test "the resistance of everything airbag related in the column itself" since that might expose someone else to a hazard, not knowing their skill level or understanding of the system. Others may interpret that as something that is done normally, and with no regard to necessary precautions. We already know that is not the case.

Vader

WIMC,

I appreciate the opinions about some of the member who may not have been good contributors to the site in the past, but please be careful about your OWN posts. There are a lot of similar user names on the site, and keeping 46,000 of them straight is not easy. If Camaro45801 is not who you think it might be, you must admit it isn't a very friendly greeting.

Administrators and moderators can check who is posting and from where, and it's fairly easy to spot trouble. Thanks for the enlightenment, but next time a PM or post report to a forum moderator might be more appropriate. The three moderators on this board would probably appreciate that, too.

Trickster

Thank you Vader. I couldn't agree with that more. As he has said, if someone has a problem with a post in a forum. Please contact the moderator(s) of that board

87IROCZ350TPI

Yeah, you're right. Sorry for jumping to such a quick conclusion, I just got pissed off about 45801's rude comments and reacted immediatly after reading them. Fisherbody86, if that wasn't you, then yeah, it wasn't cool at all and I apologize. My comments were harsh and they should not have been directed toward you. They were meant for camaro45801. You have to admit though, 45801's post did seem a little fishy. Ok, bad joke. Anyway, in the future I'll handle things more appropriately and refrain from being so "in the brain, out the mouth"(or keyboard). I'll be sure to follow the proper channels if necessary. And fisherbody86, seriously man, I feel bad about accusing you of that, I really am sorry.

fisherbody86

Ok, so we are all freinds again. And I'm sorry about asking someone else to get themselves into a possible dangersous situation. And since this topic has been beaten to death, there is no need to go any further with it either. Ok, so this post is officially done.

87IROCZ350TPI

Thanks, man.