Avoiding Common Installer Mistakes: Starters

ACDelco’s Dick Martin has seen many a warranty claim on starters and knows cranking motor installation best practices: “We still get complaints on warranty claims based on voltage drops on both cranking motors and alternators from poor grounds, which tends to drive up heat in a cranking motor. Voltage is relative to cranking speed. If you lose voltage through a positive or negative cable, then cranking speed is not where it should be and the longer cranking time needed to get the engine started generates heat. A cranking motor mounting surface may require shimming, such as the old 350’s. It’s still prevalent today; people still don’t shim them correctly.” Patrick Ttreault, customer service supervisor for Dynamic Automotive, agrees: “How important is the clearance on the ring gear? Very. Kickback can break the housing, or heat up the solenoid, which then burns, or the Bendix can be eaten up. They have to verify the clearance.” Ttreault notes that most engines have an even number of cylinders, and will tend to fire at the same places on the ring gear, concentrating wear in some areas. If the starter is shimmed at these locations, it may be too tight in the regions of lower wear. And don’t forget to clean the mounting surfaces, because the grounds begin with a good electrical contact with the engine. Dick Martin recommends a test procedure for starter system grounds: “The proper procedure is to take the voltmeter, put it on the two-volt scale, and go right from the cranking motor case to the battery negative. Some don’t have a strap, relying on other connections for grounding. Most cranking motors will accept 500 mV, but we like to see 200mV. It’s the same on the positive side. On certain applications, some of the OEM’s were using aluminum cabling, so you had a resistive connection right in the cable itself.”