A
abarthbrava
Guest
Fitting a Tachometer onto a Brava/o 1.4 s
Seems to be a popular question so I thought I would post a quick guide.
This is meant as a brief guide only - I accept no responsibility for any damage this may cause. You should get someone who knows about engines to check it is correct and won't cause any damage to your engine. Also wires should be neatly and securely attached running through piping to reduce the risk of fire and possible shorting.
For the 1.4 you need a tachometer that is for a TWO coil 4 cylinder engine - NOT single coil.
Or fiat clocks from a 1.4sx (I did not fit different clocks in my old 1.4 so im only guessing it will be possible to fit them - also clocks from other engine sizes may fit but you would have to check with someone who knows).
You should disconnect the battery before doing any wiring.
Wiring-
If fitting new fiat clocks you need to find out how they wire in - plugs/wires/etc. You then need to find out which wires/connections are for what.
From the tachometer there should be a negative wire, another wire that switches the tachometer on when the ignition is on (positive current) and 2 other wires - these both wire onto the ignition coil.
So thats 1 negative wire to a suitable earth (onto negative battery terminal or suitable car body earthing connection).
1 positive wire to a positive connection that is only live when the ignition is on - most suitable connection is the positive terminal of the ignition coil.
2 other wires - these wire one on to each of the 2 negative terminals of the ignition coil.
Coil Location and Terminals-
I don't have a 1.4s anymore so I can't get you any photos. The ignition coil is under the plastic engine cover on the right hand side (passenger side) of the engine - its the thing with the 4 HT leads coming out of it. On top of it is a plug with three wires going into it.
Two of the wires are negative and one is positive - I don't remember if they are coloured but they probably are so you should be able to work out which ones are which (i think the one that connects to the center is the positive and the 2 either side are the negatives).
Onto the positive one you connect the wire that needs positive current (the fiat clocks may already get this positive feed some other way because it will need power for the speedometer, trip counter and milometer - the fiat clocks may also have a negative earth).
Onto the 2 negative terminals of the coil you need to connect the 2 other wires, one to each.
Thats it done - start the engine check it drives ok - if its any different than how it was driving before (such as any jolting occuring) then disconnect the tachometer wires from the coil immediatley and ask your mechanic.
Note-
A tachometer for a single coil 4 cylinder engine can be connected however it only connects to 1 of the negative terminals on the ignition coil - this would result in a rpm count from only 2 of the cylinders (cylinders 1 and 4 or 2 and 3), the reading would be roughly half the actual rpm of the engine.
Hope this helps,
Stephen
Abarth Brava 1.2 16v - http://www.fpsplanet.net
Member Page - http://www.fiatboo.co.uk/members/200stephenlancs.htm
Seems to be a popular question so I thought I would post a quick guide.
This is meant as a brief guide only - I accept no responsibility for any damage this may cause. You should get someone who knows about engines to check it is correct and won't cause any damage to your engine. Also wires should be neatly and securely attached running through piping to reduce the risk of fire and possible shorting.
For the 1.4 you need a tachometer that is for a TWO coil 4 cylinder engine - NOT single coil.
Or fiat clocks from a 1.4sx (I did not fit different clocks in my old 1.4 so im only guessing it will be possible to fit them - also clocks from other engine sizes may fit but you would have to check with someone who knows).
You should disconnect the battery before doing any wiring.
Wiring-
If fitting new fiat clocks you need to find out how they wire in - plugs/wires/etc. You then need to find out which wires/connections are for what.
From the tachometer there should be a negative wire, another wire that switches the tachometer on when the ignition is on (positive current) and 2 other wires - these both wire onto the ignition coil.
So thats 1 negative wire to a suitable earth (onto negative battery terminal or suitable car body earthing connection).
1 positive wire to a positive connection that is only live when the ignition is on - most suitable connection is the positive terminal of the ignition coil.
2 other wires - these wire one on to each of the 2 negative terminals of the ignition coil.
Coil Location and Terminals-
I don't have a 1.4s anymore so I can't get you any photos. The ignition coil is under the plastic engine cover on the right hand side (passenger side) of the engine - its the thing with the 4 HT leads coming out of it. On top of it is a plug with three wires going into it.
Two of the wires are negative and one is positive - I don't remember if they are coloured but they probably are so you should be able to work out which ones are which (i think the one that connects to the center is the positive and the 2 either side are the negatives).
Onto the positive one you connect the wire that needs positive current (the fiat clocks may already get this positive feed some other way because it will need power for the speedometer, trip counter and milometer - the fiat clocks may also have a negative earth).
Onto the 2 negative terminals of the coil you need to connect the 2 other wires, one to each.
Thats it done - start the engine check it drives ok - if its any different than how it was driving before (such as any jolting occuring) then disconnect the tachometer wires from the coil immediatley and ask your mechanic.
Note-
A tachometer for a single coil 4 cylinder engine can be connected however it only connects to 1 of the negative terminals on the ignition coil - this would result in a rpm count from only 2 of the cylinders (cylinders 1 and 4 or 2 and 3), the reading would be roughly half the actual rpm of the engine.
Hope this helps,
Stephen
Abarth Brava 1.2 16v - http://www.fpsplanet.net
Member Page - http://www.fiatboo.co.uk/members/200stephenlancs.htm
