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MG TD TF 1500 - Starter Shorted?

Hey Guys, I finally got my car on the road and took my wife on a picnic. After lunch, when I went to start the car, I heard a click and saw a fume of smoke. I opened the bonnett and found that the battery disconnect had melted! I reconnected the battery and tryed to start and only got a click. We rolled down a hill and jump started the car. It drove home just fine. It looks like the starter is grounded but upon removal I could spin it on the bench using a battery charger? The terminal on the starter reads zero ohms to earth. Any ideas?

Thanks, Tom
Thomas McNamara

I don't understand "It looks like the starter is grounded but upon removal I could spin it on the bench using a battery charger?"

Is that could or could not? I can't tell because of the question mark.

If it is could, then perhaps while the switch was melting the battery discharged enough so it didn't have the power to crank the engine.

If you couldn't spin it with the battery charger, then the battery charger is too small and/or the windings have burned up. Zero ohms, is also an indication that the windings have burned. If the windings shorted out, when you when to start, then there is basically a direct short across the battery, and the disconnect switch couldn't carry all the power. So it fried too.
Blake J.

Tom

I've been there! It may not be the starter; if the resistance of the starter switch is too high, not enough power goes through the battery to the motor to drive it, all that happens is a click as the armature jumps and locks. Also the starter switch can short to earth if the mounting is worn. Your ohmeter will probably show the starter as zero ohms because it is less than 0.1 ohms when healthy - remember the starting current is more than 300 amps!

Good luck

Paul Joachim
Paul Joachim

Thanks guys, yes, I could turn the starter with a 25amp battery charger and it spun fine. The starter is now in the rebuild shop. I never heard of the starter switch contact going bad, it checks with a meter OK. If the starter chcks out I'll change the switch. By the way, any idea where the flasher unit is? My turn signals are out too.

Tom
Thomas McNamara

Are you asking where it is supposed to be, or you don't know where it is at? There doesn't seem to be a universal position for it on a TD as I've tried to pin than one down too.

The flasher unit is where you can't get at it! No seriously, on some TDs its fastened under the bonnet on the left side to the cowl or to the horn bracket. On others, it is attached under the dash to the steering column, steady brace, tool box, or any place else the guy felt like doing it that day. There could be other things wrong beside the flasher. Theres also a relay attached inside the car on the tool box. It can cause problems.

I believe the TFs had the flasher, the little metal can, attached to the side of the tool box under the bonnet.
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The switch may be repairable if that's the problem. I've opened them up. Inside you will find a large, heavy copper washer which bridges across the two terminals inside. The terminals can be cleaned and the washer flipped over to the unburned side.
Blake J.

Hello. T-series starter switches fail often- generally due to burned internal contacts. I have also seen one that had the plastic/rubber insulators totally rotted that could certainly cause a short. The switch must pass a bunch of amps while cranking- to test with a meter you would have to engage switch and check for voltage drop across the terminals- should be no voltage shown. Check cables for rubbed/shorted areas also. Turn signal problem could be flasher, but a bunch of other stuff as well-switch/corroded connection/relay problem/bad solder joint in new wiring harness (!), etc. Suggest tracing current with meter following shop manual wiring diagram. Good luck
George Butz

Tom,

I also once had problems with the turn signals. They worked fine until one day they wouldn't work at all, flashed intermittently, all at the same time, etc.

I traced the problem to the control box, not the little metal can - but the large metal box with about 8 wires running into it. In my case, the box is attached to the bottom of the tool box, inside the car - not really easy to get to. In looking at replacement costs (about $200 as I remember), I decided to take the box apart and have a look inside. After peering at the insides for a while and seeing nothing obviously wrong (like loose connections, burned wires, etc.) I determined that the clearance on the solenoids was off, and readjusted them. They work perfectly, and I saved myself $200!!

Good luck.

Larry Thompson
'51TD
Larry Thompson

I believe the owner's manual says to "operate the starter pull smartly" which in king's English, as I understand it, means quickly and forcefully. That will help make the switch last longer. The original is still in my TD, but the rubber insulators are getting tired. When it goes, I am first going to try to fashion new insulation. Those switches are dated and its nice to have the correct one for your car.
Blake J.

Hey guys, thanks for all the answers. Turns out my starter was loaded with oil! I purchased a new one and it seems to spin the engine fine. Any idea what size bolts hold the first exhaust bracket to the transmission? Thanks, Tom
Thomas McNamara

This thread was discussed between 30/05/2000 and 03/06/2000

MG TD TF 1500 index

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