Clocks interchanable

Im currently on my 3rd lot of clocks and keep changing them as the LCD screen and mpg thing never seems to work. Am assuming its a fault with the LCD as have read saying it is common they stop working or leak. Is it possible it's a wireing problem that can be rectified?  My clocks are the ones with the mpg gauge in the top centre and have a stick on right of sterling wheel to adjust them. I have seen other clocks that are similar but they have a stem coming out of the top right corner of clocks. Can I put theses in my car or do I need ones without the thing coming out the front of the clocks???

the ones with the stem on the clocks are early ones without the 1/2 switch on the indicator stalk. they'll still work you'll just find that the 1/2 switch on the stalk does nothing and instead you use the one on the clocks.

the lcd screen gets power separately to the rest of the dash, so it may be the fuse or + feed to the clocks has gone. check the red wire to the dash has 12v.

with the mpg gauge check the gearbox has the larger plug on it for the early dash, if it only has a 2 pin plug then no matter what you do its not going to work. in that case i would just get a later mk1 set of clocks without the separate mpg gauge on it

are yours from an 84 onwards cabrio?
the pcb is still avaliable for them and there was one on ebay a week or two back new old stock £39.

There seems a mess of wires behind my clocks and don't want to make worse so am prob just going to take to auto elec for them to sort. Thanks for the replys.