I looked at building one at one time. It it's cheaper just to buy it from them by the time it's all said and done. It's not just a simple cable. Has to have a ttl driver or something like that. Sorry, it's been a while.
JB4, DP, VMR V710, Sonic Tuning S1 coilovers, Hybrid Ovations, Soundsplinter 10" and Zapco DC Ref amps