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MG MGB Technical - CLOCK

The clock in my 79 MGB hasn't worked in years. However if the power is applied to it, it does hum or buzz, but does not operate. I also cannot get the little set screw to turn the hands either.

This is more of a curiosity thing. I saw on Wheeler Dealers, Edd took apart an electric clock from a Corvette and got it running again. It seemed to be an "easy do". Something to do with a spring loaded contact that needed to be cleaned and reset.

So, could I be so lucky to have the same set up in the MGB??

Cheers
Gary 79 MGB
gary hansen

nothing to lose. i did not see that edition.

i would be interested to hear how easily the bezel comes off. i have one with exactly the problem you describe - but managed to to pick up a good used one quite cheaply. stupidly, i chucked it and now would like to have it to experiment.

cannot understand that, chucking things isn't my usual approach.

G
Graham Moore

My clock stopped working a few years ago (79 B) and I opened it up to see if there was anything obvious. I ended up replacing a capacitor (about the only easily replaceable part I could see) which to my surprise got it working again (still working now, 10 years on). It's worth having a look inside the clock. Capacitors are notorious for age-related failure, it only cost a few pence.

The screw which turns the hands was gradually getting stiffer until it didn't work - a clean-up and a bit of lube sorted it.
Brian Shaw

Clocks vary. I think the Wheeler Dealer one used a conventional escapement with a contact and motor to periodically rewind the mainspring. I also think the MG ones are electronic so much less chance of doing anything unless the hands are stuck as may be the case. But Gary's does sound more electromechanical so as said, nothing to lose by digging in.
Paul Hunt

Paul is correct about the clock that Edd China repaired. It was from a '64 Corvette and all that he had to do, to get it functioning again, was to clean the points. It turns out that that '64 Corvette was purchased less than thirty miles from where I live in Northern California. RAY
rjm RAY

Hi Guys,

My clock AAU4948 on a 1980 MGB has been gradually failing over the last couple of years. I thought it was possibly due to poor connections as it would work for a few days & then stop & then after a drive would sometimes start again, only to stop again a few hours later.
Knowing the hassle involved to extract the lower plastic console , i waited until completing LED bulb changing for the heater controls & the clock itself.
Having got it off the car, i connected the clock directly to my test bench battery to find that the clock hands just pulse vibrate (as they did when still in the car when in a non working mode).
From this archive i note that Brian who has a 1979 MGB managed to repair his & i would like to try the same exercise if indeed the capacitor has failed. (I have tracked down a replacement used one with a black bezel ,which are like hens' teeth to find,still apparently working , but until it arrives i can't be sure & i wouldn't mind having a spare working clock).
Can anyone tell me how to take the clock apart?
Do i prize of the bezel and / or undo the screws on the rear?

On the matter of LEDS,out of interest, i will attach, a photo of the main instruments (which have been discussed from time to time) now that i have managed to change the oil gauge bulb
which was impossible to do until removing the glove box, face level vents as a precursor to removing the lower plastic console as mentioned above.
Cheers
Charles
Charles9

Photo of LED lit main instruments

Charles9

I don't know whether the clock is different on 77 and later models but for instruments earlier than that the chrome bezel has to be twisted so several tabs on it line up with cut-outs in the case. The tabs may need to be gently pried away from the flange on the case, but only the minimum amount to get it twisting.
paulh4

I have not got around to having a look at my non working Kienzle clock(1980 MGB LE) . FWIW I enclose some info on Kienzle clock repair.


https://www.thesamba.com/vw/archives/manuals/kienzle_clock_repair.php
C Harvey

Guys,
Thanks for your responses. As i am still waiting for the arrival of a used replacement (that aparrantly works) i am loathe to try to take my existing one apart as it is still not clear what the method of access is. I am posting 3 photos which may make it clearer to someone! Mine has 3 screw heads on the back & i wonder if the two that line up with 3 & 9 O'clock are retainers for the front face or whether they hold the internals in place.
The clock, a VDO Quartz has 218/32/1 on the side.
Cheers,
Charles


Charles9

2nd photo

Charles9

I have since removed the rubber grommet & the edge of the bezel appears to be rolled over the body with no obvious lugs to tease out.
Cheers,Charles

Charles9

I'd expect two of the screws - perhaps top and bottom, to hold the guts into the case. You can try slackening those. Perhaps the front is attached to the guts rather than the case, and will come forwards with the screws slackened.

Or perhaps by that time things were made such that you had to buy a new one rather than stand a chance of a repair. If the replacement works I'd be taking the old one apart, including potentially destructively, in case that makes things clearer for someone else to do a repair.
paulh4

I haven't crawled under the dash to inspect the clock, but the face is the same as Charles' first pix. My guess is the clock in my 79 is a VDO Quartz.

I found a few of these clocks on eBay at various prices. I would like to be sure I would be getting the correct unit.

Cheers,

Gary
79 MGB

gary hansen

Hi Guys,
Replacement clock arrives, which does work & keeps good time having tested it for 12 + hours. (The adjuster button on the front doesn't work but I will live with that as I can remove the purple wire fuse as & when required - not ideal, but at least i have a clock face that looks very close to the original).
There are differences; this has "Germany Borg" on the back with a reference 9170 which presumably is a production number. The bezel is slightly deeper as it fits over the body;marginal difference on the clock hands; the black bezel itself appears to be paint,rather than a plastic feel,that my original clock has (i will touch up the replacement with matt black paint);the body is longer & the orientation of the lighting socket is different. The clock came in a used plastic radio console together with the mouldings & housings for the heater & air controls so i have further spares or items i could sell on to reduce the overall cost of the clock!
I will attach photos for comparison purposes.
Cheers
Charles


Charles9

Charles the new clock is going backwards.
Nigel Atkins

Ha Ha!
I stopped it this am at 0937 ( the original is where it gave up the ghost).
Photo of side showing the replacement clock being longer.
Cheers
Charles

Charles9

"The adjuster button on the front doesn't work but I will live with that as I can remove the purple wire fuse as & when required ..."

It's going to be a bit of a beggar next Sunday.
paulh4

Assuming i get everything back installed in the car by the weekend i shall insert the purple fuse when the clock hands correspond to BST !
Final photo attached showing different orientation of lighting socket (i placed the clocks with 12 o'clock at the top).
I am tempted to wire in a separate hidden switch so i can stop the clock when the car is not being used for a while e.g. winter to preserve its' working life as the car is not a daily driver & i use the cigarette socket for ease re C-TEK battery maintenance which uses the same purple feed back to the fuse box).
Cheers,Charles


Charles9

I wouldn't bother turning the clock off. I used to have that when I first fitted a battery cut-off switch, but got fed-up correcting it each time I used it, and you can't do that. So did the opposite and fitted a bypass circuit just to the clock. Mine was in the car when I bought it 25 years ago and has been running for virtually all the time since. If it's going to fail then it will fail, they are usually extremely reliable.
paulh4

I've no idea with the clock and Paul (and most others) would know a lot more about it than me but with some electrical items it's the switching off and on that can strain them even switches are arcing the the tricery but that's more their problem than say the clock.

I was wondering about having a constant bypassed supply for the clock and if it might extend rather than shorten the clock's life.

Certainly on occasions it might be useful to have the car hooked up to a battery-conditioner/charger for the slow drain of the clock and perhaps other items to give a slow recharge or to leave the conditioner/charger constantly topping up. I favour a bit of both.

The easier the car is just to jump in and start it up the more likely you are to use the car during the winter when we have many better driving days than in the rest of the year. Plus there are less motorbikes, cyclists, walkers, horses and old cars on the better roads then. Use the car on these winter occasions will be good for the car and good for the owner.
Nigel Atkins

The drain of a typical clock can be ignored. It's why I fitted the cut-off switch to my V8 when I stopped using for commuting, and the alarm was draining the battery. Since then the load of the clock has not affected starting after several weeks if the weather has been bad.

Some electrical circuits can suffer more from being switched on and off, such as incandescent light bulbs and thermionic valves i.e. things that heat up, or where there is some other cause of a rush of current when switched on, which small electronic circuits tend not to have. In WW2 when Colossus was proposed for codebreaking at Bletchley Park the powers that be laughed and said they would continually be replacing valves of which there are hundreds. "Not if we leave it on all the time" said Tommy Flowers, and he was proved right. It has to be turned on and off now because of the cost of keeping it running all the time, but they have a device that reduces the power very gradually each time they turn it off, and increases it very gradually at switch-on, and the valves are fine.
paulh4

Nigel,

It was an expensive extra to have the C-Tex lead that plugs into the cigarette socket , but it does enable me to get the car out in an instant when there is a dry / salt free day during the winter without the hassle of having to disconnect a lead off the battery, replace the lid & carpet & crawl in the back & then when i put the car away, use the cigarette socket again!

Paul,

As you say the clocks are fairly robust - my first one lasted some 36 - 37 years before playing up so hopefully this replacement might see me through - i hope so because i have just spent some 3 hours getting the lower console back in with all the controls ,clock & bulbs leaving tomorrow to tighten up the controls , refit the radio / cd player whilst making sure everything still works when they are accessible! It would have been helpful if BL at the time, had made the wiring harness 2 or 3 inches longer in the lower console area as my language was not clever trying to fit one bulb holder in without disturbing another!

Cheers

Charles
Charles9

Great news Charles about your reason for the cigarette plug lead. Expensive, are they special then, couldn't you just put a connector socket on the C-Tek output lead so that you can go from a spare or inexpensively bought cigarette plug lead to battery clips just via plugs on these leads.

Anyway you posh B lads with your cigarette lighter and socket - and clock!

Nigel Atkins

I have fitted a positive battery terminal under the bonnet of my MGB. I used one of these http://www.vehicle-wiring-products.eu/product.php/565/battery-cable-junction-box-two-stud and have wired it with a battery size cable to the terminal on the starter. Not only does it make charging easy, but it is also high enough rating to allow jump starting without having to get into the battery compartment. I stole the idea from my BMW Z3 which came fitted with just such a terminal in the engine bay because its battery is in the boot, under the floor.


Mike Howlett

Nigel,

They are expensive but well made with the other end fitted with a moulded bespoke C-Tex plug that mates with either the standard length lead on the C- Tex or one of their extension leads . The flexibility means i can use it on my daily modern or my son's.

Mike,

I considered your approach which is the same as my daily driver (from the same manufacturer as you) as the battery is in the boot.
When i use C-Tech on that i substitute the cigarette plug lead for the crocodile ended lead on the + post under the bonnet rather than risk damaging the modern car electrics by using the cigarette socket.

Cheers, Charles
Charles9

Mike,
you have to jump starts Bs - and BMWs!

I know what you mean though as I carried heavy duty jumps leads in the boot of my B and once when it was fully loaded plus a loaded boot rack a rent-a-wreck asked about a jump start (he obviously thought a classic would carry leads and know about such things, and he was right). Thought about the effort of just unloading the boot rack then getting to the leads then the battery so I just asked if it would bump start and my wife and I pushed him, started in a few yards.

Those days are over, I never carry jump leads now, gave them all away and I try very hard to avoid pushing cars as I'm at the age of possibly injuring myself, which I did last time I tried.
Nigel Atkins

The thing I don't like with modern chargers and conditioners is if they have just two charging lights, one to say it's charging and the other to say it's done. It could be days, hours or seconds between the two but it always changes when you're not there or just as you turn your back and walk away.

My old 4-amp charger that my neighbour bought me is good for slow charging and by the analogue dial I can tell within seconds or minutes if the battery is picking up well and whether it'll need a very long time. I always top the battery off by using my Carcoon/Accumate conditioner (with only two charging lights). Both are decades old and only used a few times on my cars but it helps the neighbours out.

After one incident a neighbour bought a combined charger/conditioner half-price from £30 down to £15 from Lidls and it's been excellent over the winters for his car that doesn't get too much use but he insists on leaving it locked and electronically immobilised in his garage draining the battery.


Nigel Atkins

Nigel,
C-TECH Conditioners are a lot more sophisticated with a series of 7 or 8 lights
that let you know stage by stage what is happening & the health of your battery . Technology has moved on from the simple 2 light conditoners - I know because i had
one!
Cheers, Charles
Charles9

"The adjuster button on the front doesn't work but I will live with that as I can remove the purple wire fuse as & when required " Sorry if this is somewhat insulting, but when you try to adjust the hands are you first pressing the adjuster in to engage it? Had to ask!!
Allan Reeling

Hi Allan,
No offence taken - i always welcome suggestions as i have found in life that we often miss the easy answer to a problem! However, not in this case - i have indeed tried pushing the button in before turning, turning without pushing & gently pulling before turning with no success .( My old non working clock will allow me to move the hands with it's adjuster which necessitates pushing it in first).
Cheers,
Charles
Charles9

Charles,
good to know. You obviously have a more sophisticated unit than C-Tek expect a "vintage" (doesn't that make us feel old) car owner will spend on, I was thinking of something like what I find is model XC 0.8.
https://www.ctek.com/products/vehicle/xc-0-8

I don't need a conditioner (or hopefully a charger) for the Midget as it has nothing draining on it, I'd expect it to fire up after months of just sitting there, battery connected, even in winter.

Nigel Atkins

Just FWIW, here are the under =-bonnet battery terminals installed on my MGB by the SPO. Under the caps are big brass terminal studs.

Jud

J. K. Chapin

Nigel,
The C-Tex you refer to is only a 6V model,
The one i have is switchable between 6 & 12v altougth i don't need the 6v facility as i don't have a motor bike!
It does however have a cold charging option & a reconditioning option,the latter of which i use once a year as it agitates the contents of the battery to clean the plates.
Cheers, Charles
Charles9

Charles,
I must be honest and say I didn't notice it was a 6v unit I just saw vintage car, which classics are sometimes called nowadays (makes me feel old, which of course I am) and the photo that turned up was what I was expecting it to be. Hung by my own prejudice - where do I sign to join that Party.

Sorry about that, thanks for letting me know. I often say I want to try to drag some on here to the 20th century as the 21st century would be too much to expect and I'm now in that group.

Oh the shame, let's keep it to ourselves. :)
Nigel Atkins

Nigel,
Age is but a number, we are all 18 (or is it 23?) inside!
Cheers, Charles
Charles9

Charles, my brain thinks I'm in my 20s but my body just won't go along with this - actually thinking about it my brain acts like it's a lot older than it actually is. I don't know why, it should be in good condition as I've used it very sparingly.

All the best.
Nigel Atkins

This thread was discussed between 26/12/2015 and 21/03/2019

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