Can anyone explain why it was necessary/what the thinking was regarding the use of such an involved gauge system on the GT ($3K to $5K module boxes and all that)? It would seem there's far more complexity integrated into that whole system than is/was necessary.
EP I am talking a guess here. Since the car uses a ECU, most of the data is in electronic form already. It is much simpler and cheaper to just pass on the data in electronic form to electronic gauges, rather than add redundant gauges using 70s technology. The retail price of many replacement parts are not reflective of the actual production cost, but rather priced to what the market will bear with a eye to maximizing profits.
The system is rather easy to debug if you have the right tools using a VCM computer you test many of the function by sending and receiving data messages, much like a computer does surfing the Internet.
As fordgt6 has done many of the "gauge" problems can easily be diagnose with a VCM. Without one, is like working blind.
BTW, I don't have a VCM what is the part number and retail of the unit?
As a side note for those of you take want a good tach signal, it doesn't exist on the FGT! The data is only in the ECU and is sent via CAN bus messages to the gauge module. One can log it using something like an SCT box, but the data stream is "slow" and not comparable to a real tach signal. Also the FGT has a wire loop near the left rear wheel that is primary side wiring of one of the ignition coil. You can tap that with an inductive pickup for RPM, but that is only reading one cylinder and is 8 times slower than the old fashioned way of reading the primary side of a coil feeds into a distributor.
