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jimmy180sx
08-04-2010, 18:03
can anyone tell me what the watt rating is for the 2.7ohm resistor to cancel out the air bag light. i searched for it but cannto find it. i got all the band colours but that only gives the resistance values. any one help me out.
samoht
08-04-2010, 22:32
Assuming voltage is 14V (car batteries are nominally 12V, but I think the alternator charges at ~14V)
then P = V2/R gives P = 73 Watts (or higher). Which seems a bit high, but may be right.

this article http://autospeed.com/cms/A_111499/article.html covers something very similar.
(generally a good website actually).
Jez
08-04-2010, 22:35
can anyone tell me what the watt rating is for the 2.7ohm resistor to cancel out the air bag light. i searched for it but cannto find it. i got all the band colours but that only gives the resistance values. any one help me out.

Small wattage (>3w) will be fine
AP2
08-04-2010, 22:43
can anyone tell me what the watt rating is for the 2.7ohm resistor to cancel out the air bag light. i searched for it but cannto find it. i got all the band colours but that only gives the resistance values. any one help me out.

Are you sure that the resistor value 2.7 ohm is correct as that will have to disapate just over 5 amps which is why the wattage is so high @73watts.

I would have thought the 2k7 ohm would be more like a realistic value giving a wattage rating of 0.073 watts

What are the band colours you have 2.7 ohm is Red Brown Gold and 2k7 is Red Violet Red ?
Jez
08-04-2010, 22:51
Are you sure that the resistor value 2.7 ohm is correct as that will have to disapate just over 5 amps which is why the wattage is so high @73watts.

There's not 12v across the resistor. You do need a 2.7 ohm resistor :)
martinbattye
10-04-2010, 17:42
Are you sure that the resistor value 2.7 ohm is correct as that will have to disapate just over 5 amps which is why the wattage is so high @73watts.

I would have thought the 2k7 ohm would be more like a realistic value giving a wattage rating of 0.073 watts

What are the band colours you have 2.7 ohm is Red Brown Gold and 2k7 is Red Violet Red ?

the airbag unit only "checks" to see if the unit is present. i think perhaps in an impact the unit will send 12v down to it but i dont think it'll really matter at that point.!!
jimmy180sx
11-04-2010, 18:38
Small wattage (>3w) will be fine

so thats a rating bigger than 3W. also i took the airbag box thingy apart in the oem steering wheel and see that there is a resistor in it but dont no wat rating it is, colour or wattage. maybe this could work i dont know?
jimmy180sx
23-04-2010, 10:20
job done. no need for a resistor at all. just earthed the wire to the body lights out.
BBB
23-04-2010, 10:22
Are you sure it works okay? I used a 2.7ohm resistor, very low wattage and it worked fine. I though the airbag ECU had to find resistance or the circuit won't check out as okay.
jimmy180sx
23-04-2010, 10:40
wire colours for the 180sx differ from those of the s14. so the "how to's" were no good to me. i was trying to find the live wire for the horn (green in colour) with a phase tester earthed to the body of the car. when i was checking the 4 wires, 2 of them are live. one is the horn the other is for the air bag (brown in colour) when i earthed the brown wire to the body the airbag light went out.

when i start the car now no air bag light flashes which it used to previously with the OEM steering wheel. and stays off all the time. i saved myself 17p + postage from maplins. yay!!
BBB
23-04-2010, 10:46
All good then fella. :thumbs:
richy200
23-04-2010, 10:56
wire colours for the 180sx differ from those of the s14. so the "how to's" were no good to me. i was trying to find the live wire for the horn (green in colour) with a phase tester earthed to the body of the car. when i was checking the 4 wires, 2 of them are live. one is the horn the other is for the air bag (brown in colour) when i earthed the brown wire to the body the airbag light went out.

when i start the car now no air bag light flashes which it used to previously with the OEM steering wheel. and stays off all the time. i saved myself 17p + postage from maplins. yay!!

Does the airbag light come on though when you start the car? For MOT doesn;t this have to come on?

I went to maplins the other day and bought a 2.7ohm resistor to cancel the aribag light out. Which took all of 5 minutes to do :) now the light comes on when ignition lights are on and then goes out when the car is started
jimmy180sx
23-04-2010, 11:26
as far as im aware NCT (irish equivilant of MOT) doesnt take air bag light coming on into account when ignition is turned on. maybe someone will correct me. postage alone to ireland was £8 for a tiny resistor. ive tried places over here for a resistor but you have to buy in batches of 10, 50, 100's. I only want one!!