Gosling1
The tolerance will be critical in this application - a 10% tolerance (brown? band) could be 90 or 110 ohms......5% tolerance (silver band) is closer, but an ECU is probably expecting an *exact* signal of 100ohm, so 1% tolerance would be ideal.......
sorry, I am an electronics *anorak* from way back......
Varden - do the very best job you can when soldering the resistor into the circuit - any bad solder joints can add additional resistance to a circuit...
An anorak Gos??
Thats good to hear

The resistor i have on order has a 1% tolerance where as the one i tried from RS had a much higher tolerance. The bloke at RS measured the one on the ign and it was exactly 100 ohm.
The next one should be an exact match to the one out of the ign, and regarding the soldering i'm using chocolate blocks (screw down wire connectors) cos the only soldering iron i have is a POS and i still haven't gotten around to getting any decent flux cored solder either.