Hey Mudders, I recently swapped a om617 into a first gen 4runner. I wanted to keep the stock guages so I installed a DD interface with crank sensor. my DD box is recieving a signal from the crank sensor, but the tach is not working. I contacted DD and tech services suggested I may have a ballast resister in my tach. I can't find any info to support this. it's a 4cylinder tach from an 86. anyone have any luck with this kind of install. all help is apprieciated.