Engine bay electrics

[kingston-dave 0 1 Cars]

Hi guys and gals,

 

Since getting the engine back in my 1.9 Gti, I have spent many weekends trying to sort out water pipes, oil pipes and electrics. 
 

I think I’m nearly there, but I have a few lose ends that I hope someone can help with. 
 

I’ll deal with the first 2 in this post, to avoid confusion. 
 

I have 2 black wires (one either side of the engine bay, near the front) with Female connectors that look like they would Go onto a threaded connection on a sensor or similar (1st picture). Please help. 
 

The second issue is a red connector near the battery tray (2nd picture). Again, please help. 
 

Regards, Dave

[welshpug 1,678]

black wires are part of the brake pad warning light circuit, very rarely complete and working,

 

red 2 pin is an ignition switched live only used on twin fan equipped models, i.e Turbo Diesel and Air conditioning equipped cars.

[kingston-dave 0 1 Cars]

Thanks Welshpug. Wires to callipers now connected and the red plug is neatly tucked out of the way

[kingston-dave 0 1 Cars]

Now for my next problem. 
 

I have a brown plug that comes from the loom near the MAF meter (1st picture). Connected to the brown plug is a light brown plug with a short length of loom with 3 wires at the other end (2nd picture). Two wires have spade type connectors, the third wire is missing it’s connector. 
 

where do these wires go?? Please help!!

 

regards, Dave

[welshpug 1,678]

looks like oil pressure sender, switch, and alternator possibly.

[kingston-dave 0 1 Cars]

I’ve already got both of those connected. I have read about a redundant brown plug, that was used by the Peugeot dealer, could this be the one??

[welshpug 1,678]

if those are already connected then they may be for the coolant and oil temperature senders, earth each one in turn and see which of the gauges/warning lights move/illuminate with the ignition on.

[Anthony 1,003]

39 minutes ago, kingston-dave said:

I’ve already got both of those connected. I have read about a redundant brown plug, that was used by the Peugeot dealer, could this be the one??

 

No, that's comes up the back of the engine and has a brown 3 pin plug on it.

 

I can't remember the wire colours on those early looms, but from the position, could be the coolant temp sensor, high coolant temp switch (both on the rear of the thermostat housing) and the oil temperature sender (on the rear of the sump).  The later in particular tends to brake as the wire gets baked and goes brittle from the heat of the exhaust manifold, eventually snapping off.

 

If you ground each one to earth with the ignition on, the appropriate gauge will max out or warning light come on.

[kingston-dave 0 1 Cars]

That all makes sense, as now I come to think about it, I don’t recall connecting anything for water temperature. I’m really nervous about connecting a battery to the car, but it is getting to the point where I need to. 

[kingston-dave 0 1 Cars]

Ok! So here are my next two wiring issues. The first is a quite heavy brown wire with a spade connector that comes out of the loom by the MAF meter (pic 1). 
 

The second is a red/brown connector which is at the near side front corner (pic 2). 
 

more help please

Dave

[welshpug 1,678]

big brown wire should have a black 2 pin connector and plug into the shunt box, your 5 slot 3 wire plug is a fan system test point.

[kingston-dave 0 1 Cars]

Wow! We are getting there. So I can tuck the red/brown connector out of the way for now. 
 

But, what is the ‘shunt box’? And should it have another wire going to it as well if it should of had a 2 pin connector?

 

Dave

[welshpug 1,678]

shunt box is the main fused connection between the battery secondary positive feed (smaller yellow cable) and the rest of the car.

 

  the shunt box has one connector for the interior and lights, one for the engine management system and one for the cooling fan.

[kingston-dave 0 1 Cars]

I know the box you mean, bolted to the slam panel. 
 

I’ll take a look at the weekend. 
 

thanks again for your help

Dave

[kingston-dave 0 1 Cars]

Hi again. 
 

well, I plucked up the courage to connect a battery to the car, which was a result as it didn’t burst into flames. 
 

I still have a few issues. 
 

firstly, what lights should be on the dash when the ignition is switched on? I have oil light and fuel light as expected, but I also have water overheat light which was not expected, unless this goes off when the car is started?

 

Secondly, can anyone tell me where this black wire goes (pic 1)? It comes out of the loom near the coil. Think it’s an earth?!

 

Thirdly, can anyone tell me what this is (pic 2)?

 

Regards

Dave

[welshpug 1,678]

1st pic, part of the pad wear sensor wiring possibly.

 

2nd is the engine speed sensor that was used in the dealer network for diagnostic purposes.