When trying to start for the first time in the morning, my 1986 Ninety 2.5 diesel is very slow to turn over.
After four or five turns if I then stop, turn off the ignition and try again, it turns over fine and starts. The battery is less than three months old, the alternator reads 14+ volts when the vehicle’s running and there’s a new starter motor fitted.
Any thoughts on this problem?
Colin Nash, Winchester, Hants
If the battery is new and charged, and the starter is new with a new solenoid, it’s not immediately obvious where the problem is. So, it’s time to test, not guess.
First, put a voltmeter across the battery – this should read more than 12.5v. Then operate the starter. If the voltage drops right down to 10v, the battery isn’t as good as you thought. It should hold up to at least 11.5v. Note the voltage.
Next, connect the meter from the starter motor casing to the solenoid bolt nearest the motor case, then crank again. The voltage shouldn’t be any more than 0.5v below the reading that you took at the battery. If it is, you have either cable or solenoid problems.
To eliminate the solenoid, put the voltmeter across the two bolts on the solenoid. This reading should be about 12v. When you operate the starter, the reading should drop to less than 0.25v. If the reading is above this, then it’s the solenoid that’s faulty.
If you still have low volts at the starter motor and a good solenoid, strip and clean all
the earth and feed cable connections and test again, including the body-to-engine link.