When you say the cruise control id "jerky" do you mean that while the crusie controlis engaged, the car will alternate between speeding up and slowing down creating a sort of rocking motion or jerking you forward and back? If this is the case, the rebuild was not sucessful. My current crusie amp was doing the rocking motion symptom prior to my resoldering all the connections inside. A good resolder and the problem was gone. I have had two amps do the same thing. The crusie will set, accelerate, decelerate, resume, etc. But either after a while of operation or immediately upon turning the crusie on ( just depending on the day, temp, etc) the rocking motion would begin. A good resolder rebuild and the problem was gone. I have rarely seen the amps go "bad" they just get funny symptoms due to failing solder connections. They can manifest in all sorts of problems...turning off on their own, the rocking motion, not operating at all, etc. I have not ever had one completely DOA, they have all beun to work again after a good resolder session. I would recommend returning the amp to the rebuild shop, they dont seem to have done the rebuild quite right in your case. Good luck.

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Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red