Wiring Harness Questions and Mailing Instructions

Planning on sending us your harness? Take a quick glance over this page, making sure that you have everything sent to us at the same time will help expedite your order.  Please fill out our mail-in request >>FORM<< And include it with your harness or ECU.

Below you will find descriptions and examples of what you could/would be sending us for modification.

  • Engine Control Unit (ECU). (Most mk3)
  • Harness from Engine to ECU.
  • Accelerator Pedal connector with at least 10 cm of wire. (TDI ONLY)
    mk3mk4 pedal
     (Left: Mk3; Right Mk4)
  • If you want to convert to a mk4 style pedal for your mk3 TDI just let us know, its easier to get replacement pedals, and we have a bolt in bracket (HERE ) from your MK4 to MK1 accelerator pedal.
  • Engine Control Unit Engine harness Accelerator pedal plug (MK3 style)

If you are missing some of these items, no problem! We usually can supply them to you at a reasonable cost.

  • Engine Control Unit (ECU)
    mk4 ecu
  • Large connector ECU Harness, has 4 or 5 colored plugs to rain tray plenum, (or under the beetle dash cap)
    mk4body harness
  • Small connector ECU Harness has the majority of the connections to the engine.
  • Glow Plug Relay (TDI Swaps only) with it’s base and at least 6″ of wire. (pictured is an 02-up, pre-02 is under the dash)
    02up glow plug relay
  • Accelerator Pedal connector with at least 6″ of wire. (pictured on the left is the mk3 connector, Right is the mk4 connector)
    mk3 mk4 pedal harness

If you are missing some of these items, no problem! We usually can supply them to you at a reasonable cost.

Other parts you will need :

You will need these parts to complete your installation. However, we don’t need them to work on your wire harness, so please don’t send these parts to us, unless you just enjoy paying for shipping costs..

  • Accelerator pedal (mk4 on the right, mk3 on the left)
    mk3mk4 pedal
  • Turbo control valve (N75) (gas 1.8t on left, TDI on right)
  • EGR control valve (N18) *
    tdi egr
    tdi egr asv
  • Intake Manifold Flap Valve  *
    tdi asv
  • Manifold Absolute Pressure (MAP) sensor
  • Intercooler
  • Mass Air Flow (MAF) sensor *
* To make your installation process simpler for you, we can delete these items from your harness. However check local laws before doing so as you may not be able to pass certain emission tests.

The fastest and cheapest way to send a wire harness is with the Post Office. If you live outside of the USA, you will more than likely have to fill out a customs declaration form, this process is quite simple! An important note: you are not selling us these parts, rather you are sending them for repair and to be returned! So when filling out the form simply write: Automotive wire harness sent for repair, no commercial value. In the value field, put one dollar. In the insurance field, insure it for whatever amount you feel comfortable with.

To help us plan our time around the arrival of your harness please forward the tracking information to our email. BE SURE TO INCLUDE THIS FORM <<<<< Your order will be delayed significantly if it is not included with your harness or ecu..

If you insist on sending with a courier such as UPS / Fed­Ex you will be 100% responsible for all fees incurred.

Before starting the harness we will email you to ensure both parties are on the same page. If there are any missing parts or concerns that we may have with the harness, this will be discussed before any work commences. The harness will be sent back and labeled as a “repaired automotive wire harness.” Again, if you have any questions or concerns, please let us know! If you need OEM style tape for wrapping your harness you can find it HERE !

S&P Automotive assumes no responsibility for how you install or use the products purchased from us. Please check with your local laws for compliance. If you have installation questions you can always email us and/or hire a qualified technician.