Identifying Relays, Modifing Harness, Please help! Have pics.

[slowgsr]

Hey guys, Little bit of backround info on the car. Its a 1990 TSI awd. Im using an AEM EMS, and ive already modified my engine harness, that was no biggie.

As for the interior/dash harness.. I need some help! Ive removed, most of everything I know I don't need, and I know theres much more I can eliminate, im just not sure what all the relays done, which Is why I haven't touched them.

For the record, im an electrician, and I don't mind tinkering with wiring.

Heres what the car NEEDS TO WORK.

Headlights, Tail lights, Turn Signals, Horn, Front wiper only, Hazzards, Power windows/Power Door locks.

Heres what It dosen't need.

Rear Defrost system.
Rear Wiper
Any Squirters
Interior lighting, door lighting etc.
Speakers/Stereo
Day Time Running Lights.
AC and PS.
Also, Don't need any of that security/factory alarm stuff.

I kept the diming circuit you find on the dash, as well as the button/circuit to manually pop the headlights without actually turning them on.

The car has NO abs either, and As for the ignition circuit, I just need it to start when I turn the key, nothing fancy.

Please, I purchased a Haynes manual, which is pretty useless.. It didn't help me out much, I thought it would.. should have saved my money.

I searched here, searched google.. It would be really nice if someone has any type of info on which relays are what, Im not really concerned with the ones on the fuse boxes, its the ones in random places on the harness, theres also 2 small 'computer' type things.. They look more complex then relays, just wondering what there for.

Again, these relays were found on the interior harness of my 1G, but if anyone with more expereicne with DSM's could help me out that would be great, Really want to get this thing finished. I still have the stock wiring going into the bay, though the fender, across the rad support and to the fuse box.. Im just doing the interior section for now. Its enough work as it is.

Heres some pics, If I knew what these relays do, I could remove them as well as the circuitry going to them, and it would shed lots of extra wires.

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Heres a rough location.

From the TOP
1 - Rear section of harness behind drivers seat/trunk area.
2 - Rear section of harness behind drivers seat/trunk area.
3 - Im unsure where this goes!
4 - Middle area of harness
5 - Middle area (steering column)
6 - Passenger side area.

Thanks everyone!

Even some good links where I could do some self research would be great.

 

[flying_eagle]

the third is the mpi relay which is the master relay it goes right next to the ecu which is the fifth one in the picture and they go behind the radio in the center console, those are the only ones i know

 

[9!'clipseDOHC]

the third is the mpi relay which is the master relay it goes right next to the ecu which is the fifth one in the picture and they go behind the radio in the center console, those are the only ones i know

Nice guess but thats not the ECU.

slowgsr, if you post the part numbers on each of the relays someone will be able to look it up for you.

Yes the third one is the MPI relay. Also the last one is the door lock/theft-alarm control unit.

Hope this helps!

 

[flying_eagle]

? are you sure

 

[9!'clipseDOHC]

? are you sure

Yes. This is what the ECU looks like:

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Also he mentioned that he is using AEM EMS, so there is no factory ECU.

 

[slowgsr]

Thanks guys, The forth one is the cruise control unit, (speed control unit). So I removed it, and the circuity for it.

The others all stayed. I will post up some pics of the new harness and all the stuff I removed.

And #3 yes, the MPFI relay, I don't know how I overlooked that. I thought I had that one pluged in, since its not even part of the interior harness, part of the engine harness.

I didn't go 'crazy' I mean.. There is probably some more things I could have removed, but I wanted to get most of the stuff out I don't need, and add stuff I do need, and loom it all up together. Nothing worse then a rats nest of wiring!

 

[Jst4Cyl]

Thanks guys, The forth one is the cruise control unit, (speed control unit). So I removed it, and the circuity for it.

The others all stayed. I will post up some pics of the new harness and all the stuff I removed.

And #3 yes, the MPFI relay, I don't know how I overlooked that. I thought I had that one pluged in, since its not even part of the interior harness, part of the engine harness.

I didn't go 'crazy' I mean.. There is probably some more things I could have removed, but I wanted to get most of the stuff out I don't need, and add stuff I do need, and loom it all up together. Nothing worse then a rats nest of wiring!

I have heard thoughts of removing this causing the cars tail lights not working. Theory believed was that it's also part of the brake lights. Hazards worked but no turn signals...

I also just removed this due to it's name and now I'm finding these things out ...So keep us posted...Got any pics? I'll post up a few if anyone wants to take a gander at the mess