S3 STARTER CLICK AND NO CLUNK! new stream

After the comments on the previous ‘old’ post, I have decided to post my specific symptoms:

Background - I bought the V12 as a non runner and am slowly putting back all that was off the engine (lh exhaust manifolds/carbs/aircon condenser/ air drier etc)
PO did say that the starter motor was on the way out, but its been years since used on the road.

History of starter fault since I started working on it:

  1. Starter motor turned over engine (for compression test) with no problem.
  2. A few days later (with plugs back in) and ‘click’ and no clunk on trying to turn over.
  3. Removed starter motor to investigate as PO stated it was suspect.
  4. Cleaned all connections (corroded)
  5. Removed solenoid and cleaned (not bad condition)
  6. Lubricated pinion shaft (which was moving ok anyway)
  7. Bench tested starter and solenoid separately (ok)
  8. Bench tested starter and solenoid as a unit and all worked well. Lots of power and torque
  9. Cleaned the main battery connection at starter end of cable
    10 Cleaned ignition cable at starter end of cable
    11 checked engine earth strap (in good order) (also ran direct earth from engine to battery)
  10. Confidently refitted starter -
    ‘click’ and no clunk or turning over- exactly as before

12a, Took plugs out to see if it was a loading issue -
‘click’ and no clunk or turning over- exactly as before

12B. Put headlights on and turned starter - no dimming (stayed bright) -
‘click’ and no clunk or turning over- exactly as before

  1. Suspected starter relay but i was getting power to C4 and C1. I did notice that the wiring appears to be incorrect at C4. wiring diagram shows red/yellow but that cable is on C1 on my car. I cant see why anyone would have changed them in the past?

  2. Bought new relay anyway and wired as original above (13) -
    ‘click’ and no clunk or turning over- exactly as before.

  3. Decided to buy new high torque motor…but before I removed it again, i shorted the solenoid and motor contacts…
    AND THE ENGINE TURNED OVER EASILY!! Pleased but frustrated!! Repeated it several times by ‘sparks flying’ shorting with a screwdriver.
    I still don’t know what the issue is.

Motor purchase on hold until one of you knowledgable owners gives me the answer…as Im sure there are enough symptoms to narrow it down…here’s hoping

Almost sounds as though the solenoid is wired incorrectly.

LLoyd

If the law is on your side, pound on the law.

If the facts are on your side, pound on the facts.

If neither are on your side, pound on the table.

-Carl Sandburg

I don’t know from Series 3 cars but your list doesn’t indicate you’ve checked your starter ground cable connection. In the earlier series cars it’s on the left side X panel behind the booster, below the heater. If it’s iffy the current will attempt to find a ground elsewhere and if the starter actually operates the current draw can cause the much lighter gauge ground wires in the main harness to fry. If you haven’t already done so it might be worthwhile disconnecting the starter ground, cleaning up it and the contact point on the X panel, applying a little dielectric grease and bolting it down tight.

Phillip, if I understand you correctly, you connected the two large terminals on the starter solenoid to each other with a screw driver and the starter motor spun the engine. If so, now I would suggest to take jumper wire and connect 12 volts directly to the small solenoid terminal and see if it cranks.
Tom

Tom…which connection exactly is the small one? Is that the screw one on the solenoid (ignition?) or one of the copper studs?

I did earth the engine directly to the battery (line 11)

How can a solenoid Ben wired incorrectly Lloyd? What exactly do you suspect is incorrect?

Edit: I don’t know if the S3 cars are configured differently, but in the earlier cars there is a heavy ground cable that goes to body ground just under the heater. It’s a natural place to hide a keyed disconnect switch (a la Tweety). If that connection is compromised you cannot get enough juice to the starter.

This sounds like the brushes in the motor have reached end of life. Clearly the solenoid is still working (hence the click) but once the main contacts have engaged, one or both of the brushes just don’t quite contact the commutator. If you are lucky a P.O. will not have spot welded the brush tails to the terminals. (Why did they do that?.. Aaarrrgh!)

Phillip, Can I assume your starter motor and solenoid look similar to this photo, which was posted previously as a 4.2? Based on what I believe you said, you shorted post B (battery) to M, (motor) with a screw driver while the starter motor is mounted on the engine. At this point, since it turned over the engine fine, that indicates the battery is good, the cables are good, including the ground, and the motor brushes are good. Having said that, there are no guarantees, either may just be good intermittently, so do keep them in mind. Next, connect 12 volt to the S post, which is the solenoid post. You may either short it with the B post, or run a 14 ga wire (or so) from the battery to the S post. It should crank properly. Let us know.

solenoid_LI

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Thanks Tom…that’s nice and clear.
I will put it back in and give it a try.

If it is the connection to C that’s the problem, what is the likely cure?
Is it a cable issue or other?

A solenoid has 3 or 4 wires connected to it. Any two may have gotten switched by mistake.

LLoyd

Phillip, what do you mean by connection C? If you mean the S post, then you have a control circuit issue. That would include the starter portion of the ignition switch, starter relay, and associated wiring. Also, if you do not currently have the starter motor installed, and if it is a pain to do so on an S3, you may want to continue troubleshooting by testing the solenoid circuit on the car before reinstalling the SM.
Tom

Sorry Tom…I meant S.

Update is…I reinstalled the starter motor (getting pretty good at it now!)
I wired the S direct to battery and it turned over no problem…time and time again.

So it would appear to eliminate the starter and solenoid as the issue.
I have already replaced the relay so I need to check the starter switch next I suppose.

Phillip,

Hang on a minute! I wouldn’t go buying a replacement ignition switch quite yet. If your starter relay clicks when you turn the switch, I really don’t see the ignition switch as the culprit here. As others have already stated, the issue here seems to be a high resistance in some path that needs to carry significant current to operate correctly. The ignition switch just operates the starter relay and requires very little current - that’s why a relay is used. The solenoid is turned on by the high current side of the relay - that is the Contacts labelled C1,C2,C4 rather than the low current side W1,W2 which are controlled by the ignition switch. If a direct connection from the battery to the Solenoid S operates the starter correctly (as your last post said), then I would be suspecting the following components:
(A) the Starter Relay - you said you replaced it - can you confirm you got the correct model?
(B) the wiring/connections to the 3 contact wires C1, C2, and C4 of the starter relay. According to the S3 wiring diagram I have, your 3 contacts will be connected to a 12v source (C2), the S connection on the solenoid (C4) , and the ignition ballast circuit (C1). The C1 wire shouldn’t affect the starter, so it’s down to the C2 wire (N-brown) which goes to the battery source, and the C4 wire (WR - white with red tracer) which goes to the Solenoid S. I’d suggest cleaning up/tightening the connections at each end of both these wires, and if that still results in no joy, temporarily replacing each with a jumper wire to eliminate a cable broken inside the insulation.

Good luck!
-David

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Going along with what David said, you may want to check the voltage with a volt meter (with respect to ground) at C2 (supply voltage from the battery) and then C4 and C1(output from the relay) while trying to crank. All should be close to 11-12 volts.

check if there is too much voltage drop.

I have twice fooled about extensively with Saloon Starter motors Lucas 45 and M100, they would pass various tests, but still turned the motor over too slow, and pulled big current.

I ended up having them rebuilt by an autolec for about $A160, and then they worked perfectly, just saying 45+yr old SM

Great explanation David thank you. I will investigate and get back

Phillip, I see that the starter circuit appears to go through the seat belt warning system. I am not familiar with it, but maybe it could be involved. Since something is clicking, it sounds as if it is not part of the problem, unless it is the source of a voltage drop, which you will find when you check voltages with a meter. Also, do you know what is clicking? The relay or the starter solenoid?
Tom

Update:

Found a loose earth (main battery connection to bulkhead)
Cleaned and tightened…no change!

Put a link from C4 to S connection on solenoid…no change

Checked continuity from each C coonection on starter relay…all appear good.

Direct connection again to S from battery, and turns over every time.

Will check loading next at relay.

QUESTION. Where is the balast resistor?