Jim Grant's Tech Tips
Volkswagen Cabrio, Smoking Starters
What's the problem with my 99 GLX Cabrio? I have had
four starters in 13 months and the last one was smoking
and could have burned my car up.
If you’re smoking starters out of your Volkswagen that fast you need some investigative diagnosis performed before more serious damage occurs. The most common cause for repeated starter failure is due to high current draw. It takes a good amount of electrical power for a starter to start cranking the engine over, but once the starter has the engine cranking the demand for power drops. But, it is critical that the starter receive enough electrical power from the get-go to crank the engine at the right RPM. There are 2 electrical tests that need to be performed with a known good battery. The first test is called a voltage drop test, not every cowboy on the ranch understands or knows how to perform this test. The test is performed with the ignition disabled and a voltmeter. While the engine is being cranked over the voltmeter is connected to the positive post of the battery to the positive stud of the starter, not the solenoid. The voltmeter will provide a voltage reading in the area of 1 volt. If the voltage is higher like in the area of 2 to 3 volts there is a resistance issue, caused often times by corrosion. This same test is performed from the case of the starter to the negative terminal of the battery with the same allowable values. If the voltage reading is too high in either test you have a connection problem or a bad battery cable. It must be corrected. If the voltage drop test is okay then a current/amp draw test should be performed on the starter. If the current draw is too high, it indicates that the starter is binding due to worn armature, support bushings or an alignment issue. If you’re having good quality starters installed and you’re smoking them out of the vehicle every 3 or so months then you’d better be looking more closely at what a starter needs to work right. In your case it is likely that the starter is not the problem, it is just the end result of a problem.