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Many threads here detail problems involving either the solenoid or the starter- or both. I recently worked through one of my own (with my father-in-law, the best one could hope for) and wanted to share the troubleshooting and solution with everyone.
Symptoms: very often in starting the engine (almost every time), pushing on the starter button would result in a loud click but no running of the starter motor. After one, two or three (or more) pushes on the starter button, and with a loud click every time, the starter motor would eventually turn and the engine would start. These symptoms did not depend on engine temperature and could manifest themselves at any time of the day. I never had a "no start" situation but when ever I would get the click and no starter motor, my heart would skip three beats.
After checking the carbon brushes in the starter motor and cleaning all accessible connections (the starter motor ran like a champ on the bench and the solenoid never hesitated in sliding its piston back and pushing the starter gear forward) the condition remained the same once re-installed on the engine.
Engine check: we rigged a 12V lamp between the two large terminals on the back of the solenoid and tried starting the engine. Bingo! When we heard the loud click and didn't get the starter motor running, the lamp was not shining: no 12V current was arriving at the starter despite all indications that the solenoid was functioning correctly.
Solution: we took apart the back of the solenoid (see photos) to find that the heads of the large copper bolts were worn and that the large washer that is pushed-up against the two bolts in order to close the circuit was corroded. We rotated the bolts in their housings to expose fresh metal and cleaned-up the washer. Everything looked good but after further testing, the problem remained!!
Final solution: it turns out that the washer was only making occasional contact with the bolt heads despite our efforts. A second intervention involved placing fiber washers under the heads of the two large bolts (one washer each) to move them closer to the connecting washer. In this way, the contact is assured despite tiring springs and worn bolt heads.
In the first photo you can clearly see one of the larger copper bolts. The washer was placed where you can see the thin copper washer sitting over the square portion of the bolt. The same was done for the second large bolt, visible in the solenoid casing in the second photo.
You can also clearly see the large, corroded washer mounted between two springs on the central axis. This is what is pushed up towards the copper bolts when you press the starter button (or turn the key) in order to allow the full 12V coming from the batteries to reach the starter motor.
The piece I am holding between my fingers doesn't seem to be used in most of our A4 configurations while the hard-wired bolt directly opposite is the "S" post on the back of the solenoid.
Hopefully this explanation will be of some use to others with similar disquieting symptoms.
Kelly
Symptoms: very often in starting the engine (almost every time), pushing on the starter button would result in a loud click but no running of the starter motor. After one, two or three (or more) pushes on the starter button, and with a loud click every time, the starter motor would eventually turn and the engine would start. These symptoms did not depend on engine temperature and could manifest themselves at any time of the day. I never had a "no start" situation but when ever I would get the click and no starter motor, my heart would skip three beats.
After checking the carbon brushes in the starter motor and cleaning all accessible connections (the starter motor ran like a champ on the bench and the solenoid never hesitated in sliding its piston back and pushing the starter gear forward) the condition remained the same once re-installed on the engine.
Engine check: we rigged a 12V lamp between the two large terminals on the back of the solenoid and tried starting the engine. Bingo! When we heard the loud click and didn't get the starter motor running, the lamp was not shining: no 12V current was arriving at the starter despite all indications that the solenoid was functioning correctly.
Solution: we took apart the back of the solenoid (see photos) to find that the heads of the large copper bolts were worn and that the large washer that is pushed-up against the two bolts in order to close the circuit was corroded. We rotated the bolts in their housings to expose fresh metal and cleaned-up the washer. Everything looked good but after further testing, the problem remained!!
Final solution: it turns out that the washer was only making occasional contact with the bolt heads despite our efforts. A second intervention involved placing fiber washers under the heads of the two large bolts (one washer each) to move them closer to the connecting washer. In this way, the contact is assured despite tiring springs and worn bolt heads.
In the first photo you can clearly see one of the larger copper bolts. The washer was placed where you can see the thin copper washer sitting over the square portion of the bolt. The same was done for the second large bolt, visible in the solenoid casing in the second photo.
You can also clearly see the large, corroded washer mounted between two springs on the central axis. This is what is pushed up towards the copper bolts when you press the starter button (or turn the key) in order to allow the full 12V coming from the batteries to reach the starter motor.
The piece I am holding between my fingers doesn't seem to be used in most of our A4 configurations while the hard-wired bolt directly opposite is the "S" post on the back of the solenoid.
Hopefully this explanation will be of some use to others with similar disquieting symptoms.
Kelly
Attached Files
. The question is do I just clean up the solenoid as descibed here or do I get a new one? Should I get an entire starter system?
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