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Hello everyone, sorry for the delay in responding the threads. In response to bbjsw10 question, it is possible to switch from Ford's MAP sensor to VSS if the frequency at witch the VSS pulses is near the 90-160 Hz that Ford MAP sensor also pulse. This could be made simply with a SPDT switch to select from the VSS or MAP sensor outputs.
In my case, I can’t do this, because my Suzuki Swift has a VSS output of 4000 PPM. The frequency range for the Ford's MAP Sensor is from 90-160 Hz, that when converted to PPM, it falls in the 8000 PPM setting, the difference it to large between each setting. But remember that Audiovox CCS-100 also has a setting to modulate speed using the Tach Signal only. This setting works perfect if the car has a manual transmission or an automatic transmission with a torque converter that has a lock-up clutch. If it has an automatic with out lock-up, it should still work, but not as precise because there's a torque converter slippage that can not be account by the CCS-100, so when going up hills, it could fall under the set speed because the RPM will be maintained constant, but the torque converter will allow a certain amount of slippage due to the fact that it doesn’t has lock-up.
So what can be done is to change DIP Switch # 3 on or off to change between constant MPG and constant MPH. I know it is impractical to change that switch on the servo motor that’s located in the engine bay area, but if you solder to wires, one over each of the terminals of DIP Switch #3, and take those 2 wires inside the cab, then connect them to a SPST switch, this way you can control it from inside the car. You have to let DIP #3 open in the servo, so you can remotely control that setting from inside the car. When you want the signal to come from the MAP sensor for constant MPG’s, leave the the SPST switch in ON position for VSS signal. If you rather prefer a constant Speed, leave SPST switch in OFF position for Tach Only, this way it will ignore the MAP sensor’s output and only pay attention to the engine's RPM.
This is the next experiment I will be doing in my car, probably in 2 weeks or sooner. I will be posting my results and the corresponding diagram. Any questions or comments please let me know. Hope this info. is useful.
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