Thanks for the links and help. Problem ABS light on speed sensors . I first ohm sensors they were fine. Next I checked teeth on axles badly rusted ,so I removed them both and sand blasted them ,squared them up and lightly painted. After installed could go 2 days before abs light on again . This time I removed sensors again and removed rust from hubs now as soon as I get on the road ABS light on. I do not care about matching AC voltage from side to side or front to back. I would like to get the AC voltage from the same car on a working system at 40 or 50 0r 60 or 70 km per hr . This will save me a lot of time .If I match these # from a good system and my DVOM increases smoothly I know this will solve my problem,It has in the past. Thanks Dale