In my attempt to check the coil and distributor cap for fault regarding the backfiring problem, I removed the ignition coil wires without marking which goes to which terminal at the coil.

On the coil there are two terminals that I used to check the primary ohm. The two wires that are supposed to be connected at these terminals are colored 1) red/white and 2)Blue. Beside the terminals are markings 1 and 15.

I read some books that 15 is positive and 1 is negative. Question is which wire goes to positive(15) and which goes to negataive(1)terminal?

I've been to my mechanic place to spy on other volvos but I got differing results. On some vehicles I saw the blue wire on the 1(negative) terminal while the R/W on the 15(positive) terminal and some the reversal. My understanding is the R/W to the 15(positive) terminal and the Blue to the negative(-)terminal. Now, which is which?

Also, what are consequences if I put them the wrong wires to the terminal. I know I still can start the car and run it but will there be any electrical or mechanical disaster?

Thanks for all you can give.

Laozong