new clocks 2 plugs?

ok bought sum clocks from the car boot be rude not too,the lcd screen is not bleeding at all jus a slight scratch on the plastic on the front but ad a look at mine an it only has 1 plug on the underside to the right as you look face on,wots the other plug on the new 1 and would i be able to fit it to the car? if not mite sell um on?

Did you not recive any wiring diagrams and also what clocks exactly are these?? Time?? Volatgae etc…..

Cheers..

Firstly, did you buy Mk1 series 2 clocks or something else (Scirocco, Mk2 Golf, etc)?

Secondly, what does the 2nd plug look like? And are the new ones MFA - they have a 2nd plug (6 pins) which carries some of the extra functionality. You'd need to add sensors and a large style switch on the gearbox (which acts as the reverse light switch but also senses which gear the car is in), and a vacuum line to the back too I think. Does your car have this stuff to make the MFA work? etc.

For sure the original poster needs to clear things up a little to get a good answer, but the bit about the reverse light switch is wrong. First it is not needed for MFA functions and it has no means to determine gear selection. MFA does not have or need to know what gear the vehicle is in to operate.

Don't forget to smile  

GrimyFingers said

For sure the original poster needs to clear things up a little to get a good answer, but the bit about the reverse light switch is wrong. First it is not needed for MFA functions and it has no means to determine gear selection. MFA does not have or need to know what gear the vehicle is in to operate.

Don't forget to smile  

Depends which variation of MFA/display.

I didn't really mean the MFA. I meant the fuel economy meter. It flashes a yellow light when it thinks its more fuel efficient to be in a higher gear, and shows the fuel economy in top gear. I think MFA has a digital fuel economy readout? If so it would need to know which gear the car is in.

Sounds like you have scirocco/pre-90 MK2 clocks there.

as paul says some clocks (not necessarily MFA equipped ones!) have a large mpg gauge with an upshift light, this is controlled by a multi pin reverse light switch on the gearbox.
The MFA equipped clocks also have a digital MPG gauge, this works off the vacuum port on the back as well as taking readings from the rev counter and speedo sensor

I guess you could say that it senses what gear the car is in if you really want to as it does have a switch that turns the fuel ecomomy indicator system off when shifted into either high gear or reverse. But that is a bit of a stretch from sensing what gear the transmission is in.

Yes, MFA does have a read-out for fuel economy, mpg or L/100km depending on country. It also does not know the gear the car is in, it just uses input from the three items listed above and computes it and averages it based on how far you have driven. It will up-date about every 20sec. - 30sec. while driving and will compile and average the economy in position two until re-set (or it looses power for a little while).

GrimyFingers said

I guess you could say that it senses what gear the car is in if you really want to as it does have a switch that turns the fuel ecomomy indicator system off when shifted into either high gear or reverse. But that is a bit of a stretch from sensing what gear the transmission is in.

Yes, MFA does have a read-out for fuel economy, mpg or L/100km depending on country. It also does not know the gear the car is in, it just uses input from the three items listed above and computes it and averages it based on how far you have driven. It will up-date about every 20sec. - 30sec. while driving and will compile and average the economy in position two until re-set (or it looses power for a little while).

If the car has a shift-up indicator, it has a switch pack which is used to determine which gear, ie it has different switch outputs for 1, 2, 3, 4, 5. Also incorporated in this is the reverse light switch. Its the so-called "large switch", look at the gear ratio guide and note that it lists different gearboxes and whether its shift mechanism accept the large or small switch.

The logic behind the shift up light needs to know which gear the car is in to compute whether its better (fuel economy) to shift up.

paul_c said

 If the car has a shift-up indicator, it has a switch pack which is used to determine which gear, ie it has different switch outputs for 1, 2, 3, 4, 5. Also incorporated in this is the reverse light switch. Its the so-called "large switch", look at the gear ratio guide and note that it lists different gearboxes and whether its shift mechanism accept the large or small switch.

The logic behind the shift up light needs to know which gear the car is in to compute whether its better (fuel economy) to shift up.

I can only assume, I hate to assume but this time I must, that you have never worked on one of these systems, i.e. troubleshooting or repair of one. Yes, some transmissions require the use of the so called "large" reverse light switch, that is a given. What is wrong here is that is does not, nor can it, know which gear the transmission is placed in except for reverse and fith gear. How many wires run to the large reverse light switch? Now take the number of wires and try to come up with a combination that will indicate 5 forward gears plus reverse. Can't be done as there just are not enough wires or combinations of wires to do it.

It does not need to know what gear as it uses engine speed and load (vacuum). For a given engine speed and vacuum reading the up-shift relay computes that the engine is starting to lose the load placed on it and tells you to shift to a higher gear (it is not really for economy). You can do the exact same thing in your head if you have a vacuum gauge installed in your car. The reverse switch has two contacts inside which are trigered off the selector or shift rod, depending on the manual you read. The two switches are wired together just like throttle switches on Digifant engine and signal that the transmission is in reverse or 5th gear. That tells the up-shift relay to not turn on the light as there is no "next gear" to shift to even if the RPM and load were to compute to a need to do so.

Just how the relay does what it does is beyond my electronic knowlegde, but the wiring and how it functions is not. If a more detailed, as best I can, explaination is determined to be required then I will try my best but I'm no teacher.

sorry for not explaining properly easy jus post sum pic so here they are



i no on my clocks in the car now ive jus got the white plug shown on the left but wot is the other 1 for? will they fit in the golf and if so wot should work and what wont? sorry again not to clued up jus bought them cos the lcd screen aint bleed!

They're Mk2 clocks. I'd be selling them and seeking out Mk1 ones. The wires can be adapted, theres a FAQ somewhere with the pins you need to change around etc.