[ken6x6]

ive had this ongoing problem in the colder months with the 1772. the issue... the starter will turn over slow then, fast then back to slow then fast and then it will start. all this takes place in about 5-10 seconds. i have two interstate SP-40 batters which put out 425 CA and 340 CCA each. so with the two combined i have 850 CA and 680 CCA. i think that should be plenty of power for the starter. i also have a quality battery tender hooked up all the time so i know the batteries are topped off. all the battery cables are new and tight. starter is 1.5 years old. this problem only happens when its cold(45 and below). once its warm it turns over fast and fires right up. could the voltage regulator be going out?? im at a loss. any ideas??