FYI: This was completed on a 2001 Jetta 1.8T. Changes made to the electrical system from 2002 may make the install and wiring more complicated. Consult a current Bentley and wiring diagrams for YOUR YEAR and make.
Had some free time and a switch so I gave it a try.
Thanks to judoGTI for electrical help and the idea from his old thread .
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What follows are the instructions to wire an Engine Start Button in line with the cars keyed ignition. In this setup the Engine Start Button will only work with engine switched to ON. I used an Ignited Performance Illuminate Switch.
Wiring Diagram
IMPORTANT ~Disconnect negative battery terminal. While the majority of the work will be on wires that are switched off it is a good precaution to prevent shorting wires when moving stuff around.
DISCLAIMER I assume no responsibility for damages caused by this modification or errors made by anyone trying this. At your own risks as always.
![Image]()
Remove lower panels and metal panel covering relay panel.
*2 Torx 20 screws per panel (left of steering column, right of column, remove fuse box cover).
*2 Torx 25 screws for metal cover and 4 Torx 20 screws.
Remove steering column cover and disconnect ignition harness on left side.
Bottom portion of column cover cannot be removed without removing the steering wheel.
picture shows extra wiring for turbo timer
*2 Phillips screws under in front (you will need a micro screwdriver to get at them).
*Lift column cover up and use both hands to grasp lower instrument panel trim plate and pull out while holding firmly.
*Grasp ignition harness from behind (side facing instrument panel) and wiggle free. It has two guides and a center clip in addition to the spades.
Remove back clip from harness and pull out ignition wire.
*Back retaining clip (in purple) has four clips holding it. Ignition wire is red w/ black strip for automatic transmission (pictured) and red w/ green stripe or redw/ gray stripe for manual transmission.
EDIT: There are apparently some variation in ignition wire colors. Wire is of thinner gauge on early model years and on the bottom of harness. Check your Bently diagrams to confirm wire color for your year and make.
*Use a skinny metal pick on front face of harness to unclasp both top and bottom metal clips of wire and then pull gently from behind (this may take some work working the pick around and gently pushing/pulling wire).
Run switched power lead (12v ON not ACC.)
*Connect power lead to 12v ON wire of ignition harness for switch power. Wire is black w/ red stripe.
Reconnect harness.
*Test~Car should no longer start if you have done all correctly.
*Plug metal spade into end of ignition wire. Zip tie both wires to wire bundle (do not zip tie black bracket to the right of ignition wire bundle).
Run wires to relay. (pictured to the left of relay 175) I located relay and completed wiring into the stock relay block with OEM repair wires and a OEM Relay panel, but this is not necessary.
while a relay is not required for the Ignited performance switch to work it is recommended and is good practice to protect components
*Run ignition wire splice to 87 on relay. Run switched power lead to Engine Start Button input. Run a third wire from Engine Start Button output to 86 on relay. Find a 12v power source (I used the same switched power lead) and tap and run it to 30 on relay and ground 85 on relay. Depending on Engine Start Button ground as needed.
*Secure wires to test, reconnect battery.
*With relay disconnected use a volt meter and measure voltage across 12v power lead (30) and ground. This should read ~12v at least when ignition is on (or both if you tapped a constant wire). Measure voltage across wire to ignition and ground. This should read 0v and ~12 when you press Engine Start Button.
*Install relay and attempt to start car. Engine will only start with key in ignition switched to on.
If all is well install switch where desired. If installing in location of cigarette lighter the 12v plug must be carefully removed first.
Remove Ashtray
*1 Torx 20 screw under garbage/ash tray.
*Push entire tray towards front of car to unhook clips from metal retaining strap. Angle and pull out carefully. Disconnect harness for cigarette lighter and remove tray completely.
Metal strap swings up if you want to remove lower center console panel.
12v Plug Assembly Removal
*pull black garbage tray bulb cover off of back side of 12v plug assembly. Press red plastic clips on backside of plug in gently and push from back of plug through opening.
Install Engine Start Button and secure all wiring and your done!
Modified by evilpat at 9:19 PM 6-9-2008
Had some free time and a switch so I gave it a try.
Thanks to judoGTI for electrical help and the idea from his old thread .
What follows are the instructions to wire an Engine Start Button in line with the cars keyed ignition. In this setup the Engine Start Button will only work with engine switched to ON. I used an Ignited Performance Illuminate Switch.
Wiring Diagram
IMPORTANT ~Disconnect negative battery terminal. While the majority of the work will be on wires that are switched off it is a good precaution to prevent shorting wires when moving stuff around.
DISCLAIMER I assume no responsibility for damages caused by this modification or errors made by anyone trying this. At your own risks as always.
Remove lower panels and metal panel covering relay panel.
*2 Torx 20 screws per panel (left of steering column, right of column, remove fuse box cover).
*2 Torx 25 screws for metal cover and 4 Torx 20 screws.
Remove steering column cover and disconnect ignition harness on left side.
Bottom portion of column cover cannot be removed without removing the steering wheel.
picture shows extra wiring for turbo timer
*2 Phillips screws under in front (you will need a micro screwdriver to get at them).
*Lift column cover up and use both hands to grasp lower instrument panel trim plate and pull out while holding firmly.
*Grasp ignition harness from behind (side facing instrument panel) and wiggle free. It has two guides and a center clip in addition to the spades.
Remove back clip from harness and pull out ignition wire.
*Back retaining clip (in purple) has four clips holding it. Ignition wire is red w/ black strip for automatic transmission (pictured) and red w/ green stripe or redw/ gray stripe for manual transmission.
EDIT: There are apparently some variation in ignition wire colors. Wire is of thinner gauge on early model years and on the bottom of harness. Check your Bently diagrams to confirm wire color for your year and make.
*Use a skinny metal pick on front face of harness to unclasp both top and bottom metal clips of wire and then pull gently from behind (this may take some work working the pick around and gently pushing/pulling wire).
Run switched power lead (12v ON not ACC.)
*Connect power lead to 12v ON wire of ignition harness for switch power. Wire is black w/ red stripe.
Reconnect harness.
*Test~Car should no longer start if you have done all correctly.
*Plug metal spade into end of ignition wire. Zip tie both wires to wire bundle (do not zip tie black bracket to the right of ignition wire bundle).
Run wires to relay. (pictured to the left of relay 175) I located relay and completed wiring into the stock relay block with OEM repair wires and a OEM Relay panel, but this is not necessary.
while a relay is not required for the Ignited performance switch to work it is recommended and is good practice to protect components
*Run ignition wire splice to 87 on relay. Run switched power lead to Engine Start Button input. Run a third wire from Engine Start Button output to 86 on relay. Find a 12v power source (I used the same switched power lead) and tap and run it to 30 on relay and ground 85 on relay. Depending on Engine Start Button ground as needed.
*Secure wires to test, reconnect battery.
*With relay disconnected use a volt meter and measure voltage across 12v power lead (30) and ground. This should read ~12v at least when ignition is on (or both if you tapped a constant wire). Measure voltage across wire to ignition and ground. This should read 0v and ~12 when you press Engine Start Button.
*Install relay and attempt to start car. Engine will only start with key in ignition switched to on.
If all is well install switch where desired. If installing in location of cigarette lighter the 12v plug must be carefully removed first.
Remove Ashtray
*1 Torx 20 screw under garbage/ash tray.
*Push entire tray towards front of car to unhook clips from metal retaining strap. Angle and pull out carefully. Disconnect harness for cigarette lighter and remove tray completely.
Metal strap swings up if you want to remove lower center console panel.
12v Plug Assembly Removal
*pull black garbage tray bulb cover off of back side of 12v plug assembly. Press red plastic clips on backside of plug in gently and push from back of plug through opening.
Install Engine Start Button and secure all wiring and your done!
Modified by evilpat at 9:19 PM 6-9-2008
