ML320 Starter clicking once: No Ground?

What you will have to do is perform a voltage drop test. The prerequisites for this test are the battery must be full charged, all battery connections are clean and tight and all ground connections are in place.

1. With a DVOM, test the battery voltage at the battery cable ends: 12.6 needed.

2. Run a 10 gauge wire long enough from the negative battery cable to the starter. Attach eyelet on one side which gets attached to the neg. battery cable. The other end stripped for testing.

3. Attach the neg. lead of the DVOM to the end of the stripped wire (be inventive) and set the meter to reading volts.

4. ASSISTANT NEEDED. Turn the key to start and test the stud of the VIOLET wire. 12v should show on the meter. Release the key.

5. Then turn the key to start and test the stud of the heavy positive battery cable. Approx. 10.5-11.5v should show on the meter. Do not hold the key to start for any longer than 2 secs. to obtain reading.


If the reading on the battery cable stud falls dramatically, the resistance in the cable is too high and must be replaced.

If you do not understand anything, please ask first.

bula said:

Positive wire from battery goes to alternator then to solenoid. The other solenoid pole is start signal (negative) given by your key start signal. Maybe take a look at attached diagram and mark down what wire are you talking about in case above does not answer your question.

Click to expand...

What he is saying is that there was corrosion on one of the ends of cable #23.