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MG TD TF 1500 - 1953 TD charging problem help please

Im working on a TD that the owner replaced the loom and the charging system is non-op. As per the "Autobook", I connected A1 to A and have no change.
When I disconnect the field wire from the VR and apply battery voltage,the generator puts out about 16v@2400 revs.The voltage conditions w/key off: A and A1 have 12.5v, F and D are 0v. With the key on: A and A1 are 12.5v, F has 0.2v and D has 2.5v. With the motor running and at 2000revs: A and A1 are 12.3v, F is about 1.3v and D goes up to 3.8v. Adjusting the VR doesnt seem to change anything (I have used 2 different VR's). The print shows,with the key on, I should have battery v at D (via charge indicator light)
but I only have 2.5v. With D disconected from VR I do get 12.5v. I thought the generator armature coil may have a voltage drop,but the resistance from the armature connector to ground is about 2ohms, the field coil is about 6ohms. Shouldnt I get 12.5v at D on the VR since the Armature is grounded and has little resistance? Also, the indicator light that is in series with D, is it "special" meaning is the light itself in parallel with the line over to D? Or does all the current pass through the bulb filament? The fixture is the origonal type and the low fuel light is a new type socket. I hope all of this makes sence and I really appreciate any/all info you can provide. Thanks,Bill
wd graves

Bill Try disconnecting both wires from the generator. Then measuring the voltage at the armature terminal with the generator turning about 2000 revs. Should get close to 2.4 volts. Then connect F to A Terminals on the generator and repeat above test. Now you should easily get 20 volts. If your generator passes these two tests your VR is the problem.

Measure resistance from D to E terminal on the VR should see about 70 ohms. (All wires removed from VR). If the resistance measures about 140 ohms one of the coils in the VR has opened up, there is no repair! (short of replacing the offending relay).

I can convert your VR to solid - state so those and your contact problems will all go away.
Cheers,
Bob
Bob Jeffers

Thanks Bob, Ill do it....How much is a SS upgrade? Also, does it all fit in a normal looking VR as to appear "stock"?
The D-E resistance is about 60 ohms on one VR and 56 on the other.
thanks again,
Bill
wd graves

Bill,

Highly recommend Bob's work and yes, only the guts are changed...the outside looks still original. I'll let Bob answer the $$$ question but when he did mine it was very reasonable...much cheaper than a new regulator and I've not had a bit of trouble with it.

Here's his website: http://wiltonae.com/products/index.aspx
Gene Gillam

Check the gen out as Bob says first. If it is OK, any you have tried two regulators, perhaps the loom installer made an error. Make sure all wires correctly installed, maybe trace and check continuity. Also check all grounds- gen to block, block to chassis, and the ground wire from the regulator E terminal to the battery box/firewall is present and conductive. George
George Butz

Bill Check out my website www.wiltonae.com you will find costs and shipping addresses etc.
Cheers,
Bob
Bob Jeffers

Wow! Bob's SS VR conversion certainly has an attractive price. I suppose it would be good to confirm a properly performing generator before switching to the SS VR. How do you do that? Are the testers at the autoparts stores reliable? Sufficient? Able to test a '53 TD positive ground generator?

Thanks.

Jud
J K Chapin

Wow! Bob's SS VR conversion certainly has an attractive price. I suppose it would be good to confirm a properly performing generator before switching to the SS VR. How do you do that? Are the testers at the autoparts stores reliable? Sufficient? Able to test a '53 TD positive ground generator?

I was driving yesterday at dark-thirty with all lights on and working and I noticed three things:

The ammeter which usually pegs over at plus 30 amps pretty much stayed at center or a bit negative (not suprising given I was consuming a bunch of electricity for the lights);

The turn signals stopped working (insufficient poop with the headlights on to push the flasher?)

The generator light came on intermitantly at driving speeds (45 - 55 mph - no functioning tach so I don't know what the engine was turning but I'm guessing 2,500 to 3,500 rpm). It just dawned on me to check the belt condition and tension. Maybe with the extra load it was slipping. Any other ideas?

Thanks.

Jud
J K Chapin

Jud Try the tests I listed above. If it passes those two tests you are 99.9% sure your generator is OK.
Cheers,
Bob
Bob Jeffers

I'll do it.
Thanks. Jud
J K Chapin

Has anyone fitted a stealth Dynamo to a TD and if so any tips
Allan
A Key

Take the fan belt off, remove both wires going to the dynamo, join both dynamo terminals and connect the join to the battery live. If the dynamo runs as an electric motor it is OK.

Jan T
J Targosz

This thread was discussed between 11/01/2013 and 14/08/2017

MG TD TF 1500 index

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