The MGA With An Attitude
DEAD STARTER, Inertia Type - SS-102

At 05:20 PM 1/17/03 -0500, Glenn Johnson wrote:
>I think my starter just went kaput. Went out there and on first try it turned the cranked, but no ignition, then on all further tries, no turning, noise, or anything.

They burn out from too much continuous cranking, but hardly ever for any other reason. I have personally never burned out or worn out a starter motor, and I never expect to in my lifetime. Starters are pretty robust and only run for a few seconds at a time, so they tend to last forever if they're not abused. If it cranked okay once, then not, then it's probably a bad cable connection somewhere.

A common problem is the connection where the cable attaches to the starter motor. There the electrical stud passes through the metal and plate with some fiber or nylon insulators, There should be two nuts on the outside. First you tighten one nut to make a good connection between the head of the stud inside with the heavy wire inside. Then attach the cable and tighten the second nut to make a good electrical connection on the outside. If the first nut is loose, the stud is loose and moves around and doesn't make a good connection inside. If the first nut is tight, the insulators sometimes break apart leaving the stud grounded on the end plate. Wiggle the cable near the starter motor first and see if the stud moves.

Turn on the headlights, then try the starter.

If it draws a high current, like normal starting, the lights go a little dim. If it does this and doesn't turn at all, the starter pinion may be jammed with the ring gear. Put the tranny in 4th gear and push the car backwards to turn the engine backward slightly to free the pinion gear.

If the lights go dim and the starter cranks a little but slow, maybe the battery is low and needs charging, or possibly a dirty cable connector on a battery post.

If it cranks just a little and slow, and the lights stay fairly bright, then it's not drawing much current, so look for a bad cable connection between the starter switch and the starter input stud, or a loose or missing ground strap between the engine and chassis (usually a short ground cable across the left engine mount).

If there's a dead short at the starter it draws a VERY high current, and the battery voltage goes very low, and the headlights drop to a dull glow. Then you suspect a short between the starter input stud and the end plate.

If its a bad connection in the starter contactor switch, or bad connection at the starter input post, or open circuit inside the starter motor, then it's open circuit, and nothing happens, and the lights stay bright.

If there's a bad cable connection anywhere other than between the starter contactor switch and the starter motor or from engine to chassis, then the system voltage goes to zip and the lights go completely out.

If this doesn't give enough clues to figure it out, then you might have to haul out a volt meter, and start checking the Slow Cranking symptoms.

>My other electrical stuff like lights run off the battery fine. To be sure its the starter, I'd like to run my jumper cables from the battery directly to the starter. Have not gotten down to look at the starter yet, but expect to see a pos and neg post. My car is neg ground. With ignition off, what connection do I need to test to see if the starter would actually work if done direct? Is it pos from battery to pos on starter? Do I need a ground on either side of the connection, battery or starter?

Look at the battery first to see which post is connected directly to the chassis of the car. That shows the system polarity. Be sure you find the "+" and "-" marks on the battery case. Do not go by color of cables or connectors. If the "-" post is connected to the chassis ground, the whole car is negative ground.

When using jumpers from another car, always connect + to + and - to - regardless of which car is which polarity. If they are not the same polarity, just don't let the bumpers touch, or you have a dead short for the batteries in both cars.

Connect the hot cable first. Make the last connection to ground on the engine of the car needing the jump (in this case your MG). If you only want to test the starter motor by itself, connect the hot jumper cable directly on the stud on the end of the starter motor. Then make ground connection with the other cable anywhere on the engine or at the engine rear plate (bellhousing bolt). This puts the power directly across the starter. If you get no spark with the final connection, the starter motor is open circuit, something wrong inside, possibly the end post connection is loose. If you get a HUGE spark, and the starter doesn't turn at all, it's a dead short, possibly the input post is shorted to the end plate.

In any other case the starter should turn, at least a little. If your jumper cables are small wire cheapies, they may not carry enough current to crank the engine fast enough to start. Then you could double up on the cables, or let the good car run for a while to charge the dead battery before starting.

>If I need a rebuild on it, can you recommend an outfit that could do it?

Let your fingers do the walking. Check yellow pages for Electric Motor Service shop. Nothing special about an old Lucas starter. Same one used on 1950's vintage Ford P/U trucks, and about 2/3 of the rest of the world auto production of that era.

Barney Gaylord

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