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MG MGB Technical - starter problem

I have a 69 B. last year i had starter problems and I tightened the conections on the battery and the starter and pushed the car back and forth while in gear. that seemed to fix the problem and the starter worked well for a year. NOW the same issue and ive taken off all conections/cleaned and reattached; tried the 'in gear' rolling trick and I cant get the starter to crank. I just get a clicking. The charge on the batery is good. To get it home, I push started it and it ran fine. Is the changing out of the starter an easy job? should i be thinking something else? should i change starter AND Solenoid? thank you in advance. WTM
bill mitchell

Bill,

there is no magic to take the starter off the engine, it is fixed with just two bolts.
As you described the problem, it seems that there is a fault inside the solenoid, where burned points are normal after all these years. The solenoid can be canged or, on some models dismanteled and the points cleand to as new condition.
If you can do it yourself, it is not a really difficult job, otherwise you should have it serviced by a car electric service.

Ralph
Ralph

Check The voltage at the battery on the battery posts when you try to start the car. It should be around 10 volts or more when stating. Check the voltage at the starter or the brown wires at the fuse box while trying to start the car. Is the voltage about the same as measured at the battery? If it is not the problem is probably in the cables, cable terminals or poor contact between the battery posts and cables. I know it runs OK when pushed but it takes lots of current to start a car, poor connections or bad cables reduce the avaliable current at the starter. The car will run with much less current than is needed to start the car. It could also be the battery but that should show up in the first voltage check.

Clifton
Clifton Gordon

i rechecked the ground strap on the engine and it could look better.(i think it is sound but should be replaced) to check i ran ONE jumper cable from the motor to the frame.....no change. (but i will replace that strap)
QUESTION....if im thinking its the solenoid; can this bolt off w/out removing the starter. there appears to be two bolts that hold it onto the base. can it be just bolted off and changed out. thank you
bill m

I wouldn't try it without removing the starter. You need some room to move the solenoid around to disengage it from the starter. I don't recall exactly how it's done but you cannot simply pull it straight out after the attaching screws are removed.

Clifton
Clifton Gordon

Bill. You need to remove the starter from the car, as Clifton notes. (By the way, Clifton is someone who knows what he is doing.)

But, please refer to his earlier posting. You need to check some other things before doing this.

First, measure the voltage across the terminals, not the clamps, on the battery. It should read between 12.0 to 12.5 volts on a battery that is working well. Write this down on a piece of notebook paper.

Second, measure the voltage on the outside of the battery clamps. If the voltage is different, you need to clean the clamps and terminals of the battery. The two voltages should be exactly the same.

Third, hook up two jumper wires (or recruit an assistant) and measure the battery voltage as you are trying to crank the engine over. If the voltage drops below about 11.0 volts, have the battery tested. If not:

Fourth, hook up a jumper lead between the starter solenoid and the passenger compartment, (or, recruit an assistant to take the measurement) and, as the starter is engaged, read the voltage reading between the starter solenoid and ground. I have not been able to determine a definitive voltage for this test, but it should be very close to battery voltage--let us say 11.0 to 11.5 volts. If you see less than this, the battery terminal clamp, or the cable between the battery and starter solenoid, is the problem and it needs to be replaced. (As a test, connect the positive terminal of the battery to the large terminal of the starter solenoid with a jumper cable and test. If the starter works, it verifies there is a cable/clamp problem.)

If the voltage at the starter is good, you need to verify that the starter solenoid is being activated. If you can hear a "click" you may assume it is. My hearing is not that good anymore. Thus, I made up a jumper wire which fit onto the spade terminal of the starter and plugged into the the line from the starter relay/wire to the starter. This has a long wire which allows me to bring it back into the passenger compartment (or, again, recruit an assistant) to verify that power is going to cause the solenoid to be energized and operate the starter motor. This should read system voltage of 12.0 to 12.5 volts--or whatever your battery is showing with the circuit energized.

If all of these tests demonstrate that the various electrical systems are working, then, remove the ground connection from the battery. Remove the cable between the positive terminal of the battery and the starter, along with the brown wire cluster. Remove the two bolts holding the starter in place. Note which bolt goes where. They are of different lengths and of different threads. Bad thing to mix them up, don't you know. Remove the starter. Take the starter in for testing--it should test bad. If not, let us know because there is a big problem now.

Replace the starter with a good quality rebuilt unit, or have the original starter rebuilt locally.

Reconnect the wire from the positive terminal of the battery and the brown wire cluster to the main terminal of the solenoid. If, as seems frequent now days, the original starter is not available, the later model starter can be used. It has a second spade terminal above the main terminal and the terminal that the starter solenoid/starter wiring attaches to. Use a piece of the "shrink wrap" insulation to isolate this terminal (which is only hot when the starter is being cranked, but, worth isolation as a "just in case" situation). Hook up the wire from the starter solenoid/starting circuit.

Reattach the ground cable from the chassis to the negative terminal of the battery.

Start the engine.

Les
Les Bengtson

What is clicking? A 69 could have a starter relay, that came in that year. If it's that you can hear clicking and not the solenoid on the starter then it could be the relay that is faulty, or the brown or white/brown connections to it, or the white/brown connection on the solenoid. If it is the solenoid you can hear clicking then you need to eliminate external connections before removing the starter. With a voltmeter connected between the solenoid stud and starter body, you should see battery voltage i.e. 12v. Turn the key to crank, and if the voltage hardly drops then the problem is inside the starter. But of the voltage drops right down, it is in the connections to the starter. Repeating the test with a body ground, and on the battery posts, should reveal where the bad connection is. However a bad connection feeding the starter usually shows itself as chattering, and/or lights dimming right down. With good connections and a good battery you should see about 10v during cranking.

A 69 should have a pre-engaged starter i.e. solenoid on the starter, so rocking the car back and fore in gear normally has no effect, unlike with cars with the earlier inertia starter.
Paul Hunt 2

This thread was discussed between 30/07/2007 and 02/08/2007

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