I tried playing around with it some more still not working.... Turns out I bought a 1995 Volvo 850 turbo, where I could verify the mileage under the hood (it worked great). My home-made electronic thing was meant to be used if I bought a 1996 or younger... Even on my "new" 1995 Volvo I cou...

So yes, the part number is 276-0209. and i now also saw that it says "with integrated resistor" underneath the ratings. I forgot to post that earlier. Sounds like I should go ahead and test the same thing without the resistor then, right?

I'll have to check - i left the stuff at work so won't be able to reply until Monday. Are you saying that if it does have a resistor included, I won't need the 1k resistor and just take that out and try it? If I'm not at risk of frying the car's electronic, I can certainly try that, maybe that's why...

Thanks for the tutorial :) I used the following - That's what is writte on the packages. RadioShack 5mm Red LED, 12VDC, 20mA, 1.5mcd RadioShack 1k-Ohm Metal-Oxide Resistores, 1 watt, 5% tolerance SPST Momentary Submini Pushbutton Switch - Contacts rated 0.5A at 125VAC/250VAC. In testing it with just...

I tried again, different length pushing the button and also switching around pin 5 and 7. Pin 5 is for signal ground per link below and Pin 7 for K-Line. I'm not an electrical engineer, but I thought I just try around. When switching it around, the light is on all the time, I then tried pushing the ...

I don't even get the light to turn on no matter how many times I press the button. So it's not a matter of waiting for it to go off...

I have built this today - looks very similar to your picture - i also included a SPST switch though (always open one). I tried testing it on my '98 V70 but it didn't work. none of the trouble codes are being indicated. Basically I get a red light each time I press the button (lets say one time a lon...