MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - New Dynamator Not Working!

Installed as directed, wired as per directions and it produces no juice. Run a test instrument on it and it produces no voltage. The field wires are hooked up as drawings illustrate, charging wire also. No voltage. Does anyone have a clue what's going on? Has anyone else run into this situation? I'm about ready to pull this thing out and put the dynamo back in. PJ
PJ Jennings

No sure if you are + or - earth, but on the - earth if the ignition bulb is blown or loose it will not charge as the feed goes through the bulb.
B W Wood

Is yours positive or negative ground? Haven't seen a negative ground unit on the market for a long time.

First off, I found it would not charge at idle, much like the generators. It needs some RPMs before charging, like 1200 or so.

I also discovered, with no accessories on, it would self excite when revved up and charge with nothing attached to the field terminal on the frame (not the power terminal on the end). You might try this to confirm it does produce power. We were actually driving it this way after the field wire came loose. However, with headlights on, it wouldn't start charging.

You may try touching a hot wire to the field terminal momentarily and then run the RPMs up to see if the field excites and the ammeter jumps to the + side.

I seem to recall the voltage regulator/brush assembly is the same as one of my old, cheap Mercedes units, but that's for a negative ground alternator.
JIM N

I do not believe the Dynamotor brand has a Field connection. The smaller connection is to operate the warning light and possibly to provide self excitation as there would be no significant voltage on the alternator side of the warning light.

Something is seriously wrong with this unit.

Peter
P G Gilvarry

Sorry to hear about the problem, PJ. I'll bet that it has to do with the positive ground system. I've lost track of how many positive ground pertronix owners I've had to help in the past 20'ish years. It's almost always been a problem of how to interpret the positive ground wiring instructions. They're seldom logical. I've never seen the wiring instructions for a positive ground Dynamator. Closest I've come is Mort's wiring diagram. Any chance that you could send me a copy of the wiring diagram that came with the unit? Did you install the relay inside of the dummy voltage regulator?
My Dynamator (negative ground) starts charging at about 900 rpm, slightly above my 750 rpm idle. Jumps right up to 30 amps to replenish the starting charge. Bud
Bud Krueger

I didn't mention this fellas, but DHL who delivered the unit to me left a note in the box stating that they had to re-package the unit as it was damaged when they received it. Looks like the box was dropped on a hard surface, as the Dynamator actually punched a hole in the side of the original box. I didn't think anything of it until now. The seller has been notified. PJ
PJ Jennings

The seller in the UK responded to my message stating that the unit was possibly internally damaged when dropped and they are sending me a new unit! Told me to trash the one I have as it's too expensive to send it back when they would more than likely trash it anyway. That's quite a company! PJ
PJ Jennings

Apparently they're made in China and the spare bits aren't available, or maybe worth it, to fix them. So maybe useful to keep this one for spares if you can work out what went wrong. A diode?
Peter Allen

I know someone who has an electric motor repair service who wants to look at it, worth a try. PJ
PJ Jennings

I can well see what Peter has put as I've had the same for another different product that is now made in China and no spare parts are made for it at all. It has a three year warranty so I guess you get a complete replacement even if a small part on it is faulty and have to buy a whole new unit when out of warranty - in my case 20% discount on the not so well made Chinese unit but still sold at the previous UK made retail price.

A Dynamator is say £160 retail whereas the British made Dynalite is say twice the price retail.

The Dynamator production is fine in the short term but if it means the likes of Dynalite go out of production then that leaves what could be in the long term the expensive throw away Dynamator.

What follows this should be a familiar story to those of you in the USA, and we're very much the same in the UK. Once these production places go can't always return when needed.

Buyer beware.
Nigel Atkins

PJ,
The first one they sent me was faulty and I had the same experience as you did in that they sent me another one and told me to trash the old one. My TD is positive earth and has a Petronix ignition. I had difficulty with their installation instructions and created my own schematic. It even got Bud Krueger seal of approval.
Mort


Mort Resnicoff

Well, instead of replacing it they refunded my monies! Said they're out of stock anyway. So I have a piece of useless wall art, I'll keep it as a reminder.
PJ Jennings

Possibly Suez backlog.

Ships were queuing or taking the long route round, then there'd be queues at the port for off loading, there'd also be a wait for empty containers so these were (are?) delayed from being returned to be refilled.

Maersk the world’s largest shipping company said at the start of April that global supply chains were likely to be disrupted until second half of May.

It's always been clever to balance on a tightrope, until the fall.

Try AliExpress, you'll probably find them without a label at unbelievably low prices but probably one or more models will be as the one you ordered, order three or five or more to cover the odds of doesn't work, works for a short time, is great. Or by odds you might get three, five or more that cover the range of possibilities or five that are great and you can pass on those you don't need.
Nigel Atkins

Probably the reason they're out of stock is that they have sent out so many replacements for ones that don't work, they don't have any left! I would never buy another one. At least I got my money back, but no price on the aggravation I went through.
PJ Jennings

Buying cheap can be expensive in many ways, when there's a race to the bottom for price it can often mean for overall quality too, and take many other things to the bottom too. We in the UK and USA should know this by now. For those that haven't yet realised there'll be many, many reminders in the future.

In the UK we gave away the family silver long ago along with vital utilities and control, I'm sure USA citizens will find they've done much the same. We may just about for a while remain 1st world but very much a long way from the top of the league.

Nigel Atkins

The frustrating thing about today is anything remotely affordable is manufactured in the Far East (OK, I exaggerate a little). Nothing wrong with that per se. However, to ship it half way around the world and sell it in the West for the price they do there have to be compromises. Whether it's that it's flawed technically, lacklustre components, no back up service etc.

I'm no expert, but one of the issues with an alternator is keeping them cool, but these things are very much enclosed. Also, when one Google's the brand, PJ's experiences are not isolated. The fact that they're willing to write off the cost of the item is some indication of how cheaply they buy them in.

I'm still running old Lucas C39/45 dynamos that are sixty/seventy years old - easily replaceable brushes, and bushes (bushings!). Most of the clever stuff is in the control box, and one can get those, too.
Peter Allen

Just to remind everyone there is an alternative, it's British made and it now comes with a 'Lifetime warranty'.

https://www.powerlite-units.com/dynalite-alternator-conversions.html

"Designed and manufactured by highly experienced auto electricians in West Midlands, UK. The Dynalite aims to bring together modern alternator technology with the classic looks and appearance of a Dynamo."

"ALL DYNALITES - NOW - WITH A LIFETIME WARRANTY!

We are so confident of the advantages of our product over other units, we are introducing an industry exclusive Lifetime Warranty on all new Dynalites*. No hidden catches – if your Dynalite fails, simply send your unit to us with a fully completed warranty form (available from our website) and if it has failed due to a faulty component we will repair your unit completely FREE OF CHARGE

Notes
*subject to terms and conditions. Please see our website or contact us for a copy of our trading terms and conditions and Dynalite warranty policy."

But they're twice the price of the Dynamator and many have found the Dynamator to be fine (past production?).

I've no idea how good or not the Dynalite are, I'd hope that they're well made as I live in Britain and we need such things to be, well, made here, and sell at a reasonable price. I've had a Powerlite hi-torque starter motor for many years.

I'd guess that Powerlite have seen the Dynamator situation and to differentiate their product and justify the higher price they've come up with the marketing of the Lifetime warranty.

https://www.powerlite-units.com/dynalite-alternator-conversions.html
Nigel Atkins

This thread was discussed between 16/05/2021 and 27/05/2021

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.