Intermittent starting issues are the worst. They’re hard to diagnose, and the process can leave both owners and mechanics frustrated with each other. AAA’s Car Doctor John Paul offers some advice:
Q. I recently purchased a pristine 2005 Grand Cherokee. This Jeep only has 44,000 miles on it and spent most of its life in the former owner’s summer home. It has an intermittent problem starting.
Sometimes it cranks right over, and other times it acts lie the battery is dead. I have had the battery tested and the shop said it is fine. I took the Jeep to the local dealer and they could not come up with any diagnostic code, and said it may be the starter. The dealer quoted $210 for labor and $225 for the part. I don’t want to put money into repairs without knowing the problem. Do you have any suggestion?
A. In this vehicle, the starter shouldn’t draw more than 250 amperes during normal operation. I would be a good idea to test the starter with the engine cold and after it has fully come up to temperature. A good repair shop should also carefully inspect both battery cables and other associated wiring, looking for problems.
It is very important when performing this type of diagnostic work to perform a voltage drop test. A poor engine ground caused by corrosion could be the problem. This is more likely if the former owner’s summer home was near the ocean, where salt air and water are hard on electrical connections.
John Paul is public affairs manager for AAA Southern New England. A certified mechanic, Paul tests dozens of new cars each year and also hosts a radio show on AM 950 and 550.