Wiring harnesses problems

you won't find a provision for a voltage regulator on a Rally dash its built into the fuel guage and can play all kinds of havoc stop and call "Redfish" now before you get it all together , He makes and sells an electronic replacement he calls the IVR get one and get him to walk you through the surgical removal of the old one { it has to come out } , you may as well do it now while the dash is open or you'll probably end up doing it later . He is also the guru on wiring and can probably walk you through your other problems as well