What's this plug for ?

[Dazza the Stag]

I found this plug wrapped around my brake line in the engine bay. The black wire that comes out the back then disappears into the loom under the petrol filter.

any ideas what it is ? Everything seems to run well but it must do something ?

thanks
image.jpg
darren

[73stagman]

PDWA switch. Brake warning light switch on lower rear section of passenger side inner wing

[Danny]

Thats from the brake pressure warning switch.

Danny

[73stagman]

Depending on what year your car is and apparently which bloke got to put it together will determine how it is supposed to be wired.
Some run in series with the oil light and some run in series with the hand brake warning light. If it has been re wired at any point it could be none of the above. Not very helpful I know.
It might be a matter of getting the multi meter out and seeing if it is live at all. (It might be disconnected at the other end as well!)

[pitzey]

Mine was disconnected as well , i plugged it back in and the red light stays on ??? so i have unplugged it again.

[Dazza the Stag]

Ah - I did wonder why that warning light never came on anymore - it must have been the garages solution to the problem ! Lol
many thanks - at least it's nothing too critical

[73stagman]

Its actually quite easy to reset the warning light....Its described in the work shop manual and it worked for mine. Others have made a tool to keep the valve centred whilst bleeding the brakes.

[73stagman]

If its disconnected you get no warning if there is a fluid loss in the system until you get no brakes... usually that will be too late to do anything to help. The light is usually checked at start up with the oil pressure light system or whenever the hand brake is applied when the ignition is on (I think that's the way its wired .... mine is wired to the oil pressure light so cant be sure about the alternative)

[pitzey]

Will have to check mine out then .

[DJT]

Dazza and Pitzey

No matter how it is wired up in relation to the oil light, it is important that it is connected and set correctly. The switch can be removed from the PDWA without fluid loss and the shuttle moved using a small screwdriver to slide it to the centre. Whoever bled the brakes last was a bit heavy-footed and displaced it, triggering the warning light.

This thread shows what the PDWA look like inside.

http://www.stag.org.uk/forum/showthread.php?23645-Leaking-PDWA-amp-brake-fluid&highlight=PDWA

[73stagman]

I couldnt move mine with a screwdriver. It moved easily and obviously when I was bleeding the brakes. I just cracked a front bleed nipple and pumped the pedal hard whilst the ignition was on and the light was lit.... the light was on when I started, it flicked off and then back on again and there was a distinct "feel" in the brake pedal as the light flicked off and back on so I knew that the valve moved. I then closed off the front bleed nipple. I then just cracked a rear bleed screw and very carefully pressed the brake pedal again with the ignition on again and the light lit there was the same distinct "feel" through the brake pedal and the light went out. Then the valve was centralised and the light was out.
An added advantage is that I know the valve works!

[DJT]

I couldnt move mine with a screwdriver. It moved easily and obviously when I was bleeding the brakes. I just cracked a front bleed nipple and pumped the pedal hard whilst the ignition was on and the light was lit.... the light was on when I started, it flicked off and then back on again and there was a distinct "feel" in the brake pedal as the light flicked off and back on so I knew that the valve moved. I then closed off the front bleed nipple. I then just cracked a rear bleed screw and very carefully pressed the brake pedal again with the ignition on again and the light lit there was the same distinct "feel" through the brake pedal and the light went out. Then the valve was centralised and the light was out.
An added advantage is that I know the valve works!

Yep, that's the proper way to do it.....

Sometimes it it can be quite frustrating chasing it back and forward, which is why I made a little tool to keep it central whilst bleeding.

[fedex]

the clips on either side of mine were snapped by the previous owner, anybody have a spare about with the wire, can't find one anywhere to buy new.

[DJT]

the clips on either side of mine were snapped by the previous owner, anybody have a spare about with the wire, can't find one anywhere to buy new.

http://www.ldparts.co.uk/shop/shop.php?c=viewproduct&pid=829&cat=30&sid=sid8b19953e85f4ac27a56860d6260ea912

[73stagman]

Just one word of warning.... If the switch has been disconnected by a PO then the wiring might not be OK to just pug it back in. It will need checking properly. Brian Crossy has a car with the plug disconnected and when we connected it clouds of the very rare Lucas smoke were emitted from behind the dash. We collected it of course and now you can buy jars of it on ebay if you need any. unfortunately we haven't fixed his switch yet and its still on his "To Do" list.