93 RX-7 with SM4 install ?'s

[Broken09]

Hello all. I have a couple of questions I hope can be answered by some on here. I'm using the SM4 with R500 CDI on a 93 RX-7 2 rotor.
1) The diagram I received for my application shows the trigger ground for the R500 going nowhere. Not to a ground not to anything else. I want to make sure that I'm not supposed to use this lead. Am I right that it can be cut?
2) Which outputs are ideal for controlling fans? Should the PWM be used or others. I was planning on setting the computer up to kick one fan on at a lower temperature and then trigger the second fan at higher temps. This would of course be done using two outputs I'm just unsure if it's best to use a simple On/Off output or the PWM's. Any ideas? Thanks

[Ian]

Hello all. I have a couple of questions I hope can be answered by some on here. I'm using the SM4 with R500 CDI on a 93 RX-7 2 rotor.
1) The diagram I received for my application shows the trigger ground for the R500 going nowhere. Not to a ground not to anything else. I want to make sure that I'm not supposed to use this lead. Am I right that it can be cut?
2) Which outputs are ideal for controlling fans? Should the PWM be used or others. I was planning on setting the computer up to kick one fan on at a lower temperature and then trigger the second fan at higher temps. This would of course be done using two outputs I'm just unsure if it's best to use a simple On/Off output or the PWM's. Any ideas? Thanks
1) If you are using the CDI with an Autronic ECU there is no need to connect the trigger ground. I don't think there is any wire to cut.

2) If you have conventional relays switching the fans then use On/Off outputs. Relays are not suitable to be driven with PWM signals (other than 0% and 100%). If the fans have variable speed controllers that operate with a PWM signal then you can use PWM outputs or a software PWM function (of suitable frequency) through a normal output.

[Broken09]

1) If you are using the CDI with an Autronic ECU there is no need to connect the trigger ground. I don't think there is any wire to cut.

2) If you have conventional relays switching the fans then use On/Off outputs. Relays are not suitable to be driven with PWM signals (other than 0% and 100%). If the fans have variable speed controllers that operate with a PWM signal then you can use PWM outputs or a software PWM function (of suitable frequency) through a normal output.

Thank you very much for the quick response!