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Ford Voltage Stabiliser
russbost - 10/10/23 at 01:10 PM

Hi Guys

Just sorting the wiring on an old kitcar (Cortina wiring loom) which has a voltage stabiliser which I suspect is inop - is there any easy way to test, IIRC they create 5V by intermittently breaking the 12V feed which makes it impossible to test with a "normal" everyday multimeter.

I've tried earthing the wire from the fuel sender unit which I would expect to send the fuel gauge to full & no reaction, but I don't actually know if either the fuel or temp gauges work either!

I can buy an adjustable, solid state voltage stabiliser for peanuts off Ebay, but would that work as it doesn't function in the same way (just seems like it would be a much more sophisticated & more reliable way to stabilise voltage)

I can buy a replacement for the original for around £15, but don't want to purchase only to find I've not cured the problem!

Re wiring, I assume I am correct that the case is earthed, 12v is fed into either terminal & the other goes to the gauge - is it imortant which terminal is fed - I can't find any info on - the Cortina manual I have just shows it as part of the instrument cluster, hence no wiring ID & doesn't mention the voltage stabiliser anywhere so far as I can see!

Grateful for any info

TIA, Russ


cliftyhanger - 10/10/23 at 04:04 PM

Yep, modern repolacements work fine. But ideally I "think" they need a cap or something added, though many don't bother.
Triumph stabalisers work the same but produce an average of 10V. It is done with a bimetallic strip producing 12v then 0 then 12 etc etc, so a digital meter should change from 5V to zero and repeat, an old analogue meter is easier to use though.


russbost - 11/10/23 at 07:56 AM

quote:
Originally posted by cliftyhanger
Yep, modern repolacements work fine. But ideally I "think" they need a cap or something added, though many don't bother.
Triumph stabalisers work the same but produce an average of 10V. It is done with a bimetallic strip producing 12v then 0 then 12 etc etc, so a digital meter should change from 5V to zero and repeat, an old analogue meter is easier to use though.


Sorry, probably being thick, but what do you mean by a "cap", the ones I've been looking at can be adjusted to give out any required voltage


obfripper - 11/10/23 at 09:45 AM

A regulator from a Mk5 cortina is electronic and should be repairable if it has failed, mk3/4 uses a bimetallic mechanical regulator as you've described and is not repairable.
Also the original gauges are damped, so won't react instantly to earthing out and may take 30 seconds to do a full sweep.

More info here:
https://www.locostbuilders.co.uk/forum/5/viewthread.php?tid=220012

As used in the original instruments, the regulator plugs into a socket on the instruments and can't be fitted wrongly, it reads that you might have separate aftermarket gauges, so you're more likely to have a 10v smiths type regulator which should have the pins marked B and I and uses the case for earth. The I connector should be a female spade to prevent mixing up the battery and instrument connections.

Alternative modules like the following could be used:
https://www.ebay.co.uk/itm/262001691410 - this is a fixed 5v module, there are adjustable ones if you search ebay for "mp1584" that would replace a 10v regulator once set correctly.


Dave


russbost - 11/10/23 at 10:19 AM

quote:
Originally posted by obfripper
A regulator from a Mk5 cortina is electronic and should be repairable if it has failed, mk3/4 uses a bimetallic mechanical regulator as you've described and is not repairable.
Also the original gauges are damped, so won't react instantly to earthing out and may take 30 seconds to do a full sweep.

More info here:
https://www.locostbuilders.co.uk/forum/5/viewthread.php?tid=220012

As used in the original instruments, the regulator plugs into a socket on the instruments and can't be fitted wrongly, it reads that you might have separate aftermarket gauges, so you're more likely to have a 10v smiths type regulator which should have the pins marked B and I and uses the case for earth. The I connector should be a female spade to prevent mixing up the battery and instrument connections.

Alternative modules like the following could be used:
https://www.ebay.co.uk/itm/262001691410 - this is a fixed 5v module, there are adjustable ones if you search ebay for "mp1584" that would replace a 10v regulator once set correctly.


Dave


Ah! I should have said originally, the fuel & temp gauges are Smiths units, any way to tell if those are 5V or 10V, if they're 10V & the unit I have is a Cortina one at %v, that could account for them not working!

It's weird isn't it how we have these gaps in our knowledge - I've spent my whole adult life either working on cars for work, hobby or general interest, yet have never really had any dealings with voltage stabilisers/gauges of this type!


russbost - 16/10/23 at 09:31 AM

Just for info, turns out Smith's gauges are 10v, so I've ordered a 10v unit off Ebay, will report back with findings !