Aftermarket Speedometer Issue

[MarshallDillon]

Recently installed an aftermarket GPS speedometer with a built in antenna in my 2003 GTI (non LE). The company I bought it from (Faria Beede) said that all it needed was power and a ground. So I looked at the GTI wiring diagram for the gas gauge/ low oil and found the power and ground wires that it uses and cut/ spliced these wires. I also had to cut the blue and pink wires to get them through my hood but that’s another story. Upon first starting everything looked like it’s working (oil light came on for its check and speedometer checked itself as well). Now neither the speedometer nor the gas gauge/oil light work, although the machine starts and runs properly. I’ve attached photos from the gauge manual as well as the wiring. What could be the problem

 

[etemplet]

Since everything else stopped working I'd check the wiring. I have a Candoo GPS. It has issues which may be due to metallic paint I have on the ski. I think the best option is the factory version. Prices are ridiculous but speedometer is a novelty thing. Only top speed matters to me as it shows me the performance of the ski. Then again a GPS on the mobile phone does the trick.

 

[mikidymac]

I would disconnect the aftermarket gauge and see if the stock ones start working again. It might be pulling too much power or causing a internal short/resistance. The electronics on these are just minimum so it could be pulling too much power from the MPEM.

 

[MarshallDillon]

Yes disconnected now and oil light/ rule gauge are still not working. I was wondering if I should supply an external ground to the black lead and external power to the purple lead. Thank you