mystery wire by the oil filter

[White2505 0]

Theres three wires come out by the oil filter

 

a plain yellow which is currently disconnected.

a blue and white (i think) which is also disconnected.

and a blue and something (can;t remember right now) which is connected to the oil temp sender.

 

so whats the yellow wire for? and what about the blue and white one?

[olly elworthy 0]

all raddos have that spare wire, dont worry about it mate,,

[White2505 0]

I have two that are disconnected though.

 

I think the blue and white is spare but need to know what the yellow wire is for

[Henny 0]

Yup... what Olly says is true... it's a spare, probably for the optional oil pressure gauge, but no-one's ever confirmed that... 8)

[corradophil 3]

Yup... what Olly says is true... it's a spare, probably for the optional oil pressure gauge, but no-one's ever confirmed that...

 

If I manage to get my oil pressure/volmeter pod, I'll be looking into where this mysterious little wire is going to.

[White2505 0]

So, it's confirmed that of the three wires that come out by the oil filter TWO are spare???

[Henny 0]

no, only the blue/white should be disconnected... the other should go onto your oil pressure switch

[White2505 0]

Okay, now I'm confused

 

I have a 1.8 16 valve it has THREE wires that come out of the wiring harness by the oil filter. One goes to the oil temperature sender as read by the mfa presumably.

Cant remember the colour but I think its blue and something.

 

I have a blue and white wire which is terminated with a connector block but is clipped to the harness in such a way as to make me believe this is the spare that everyone is mentioning.

 

The yellow is just hanging around as a bare end, it must clearly have been connected to something at some time but as I dont have a pressure guage I cant see what.

 

Are there two sensors that should be connected up by the oil filter??

[mgbv8mike 0]

Blue/white is definitely for the oil pressure gauge, according to Bentley., I can't find mine (VR6) so I have run a wire from the auxilliary gauge into the engine bay, and bought a VDO sensor (no360 006D).

 

Does anybody know which sensor it replaces, there appear to be two on top of the oil filter housing, but I was told that the sensor is somewhere on the engine block ? A pic would be handy !

 

The connections on top of the sensor are marked 'G' and 'WK', any ideas which is which ?

[White2505 0]

Okay, have answered the yellow wire question, its the oil pressure alarm buzzer.

[RW1 0]

For a 1.8ltr 16v........

 

Blue/white is oil pressure gauge sender signal.

 

Yellow is oil pressure 1.8bar for led & buzzer in dash clocks module - normally closed under pressure (main bearings).

 

Blue/black oil pressure 0.3bar for led & buzzer in dash module - normally open under pressure (cylinder head).

 

Green/black is oil temperature sender signal.

 

---------

 

"G" on dual pole oil pressure sender is the signal wire connection to the gauge.

 

"WK" is connected to the Blue/Black wire. (This is a 0.3 to 0.5bar normally open under pressure switch.) WK connection should short to the sender body if tested off the engine. It cannot be connected to the Yellow wire as the dash module logic will set off the buzzer and oil pressure LED as the module on this wire is looking for a pressure switch that has gone closed circuit when oil pressure is present and WK goes open circuit when under pressure.

 

The oil pressure switch connected to the Blue/Black wire is removed and the oil pressure sender is substituted.

 

---------------

 

The module logic works like this.....

 

As the engine runs it looks at both switch conditions along with rpm & time.

 

The 0.3 bar goes closed circuit for loss of oil pressure and the dash oil pressure module works as an instant response to the switch closing ie. loss of oil pressure at the cylinder head. Loss of oil pressure is detected, the buzzer and oil pressure LED come on as long as the condition is being detected.

 

The 1.8bar switch goes open circuit for loss of oil pressure and the module senses this must be happening at about 2,000rpm & above (main bearing oil pressure loss). It waits for about 20 seconds to see if the low oil pressure condition is transitory. If still low after about 20 seconds, it activates the buzzer & dash oil pressure LED. They stay on even if the oil pressure improves and can only be reset by turning off the ignition (temporarily) ie. you ain't suppose to run the engine again until the problem is found - check oil level, if still there at above 2,000 rpm & 20 seconds, don't run the engine again until examined by a mechanic.

 

.

[mgbv8mike 0]

Thanks RW1,

 

I checked the dual sensor, and the WK contact appears to be shorted out, am I right in thinking that I'ts one of the sensors on top of the oil filter housing that I'm substituting, presumably I should be able to identify the blue/ black wire .

(VR6 engine)

[White2505 0]

Had a bit more time to look into this today.

 

On my valver there are two sensors on top of the housing the oil filter screws onto.

 

The one nearest the front of the car is the temperature sensor and had the blue/black wire to it.

The one nearest the block is the low pressure sensor and should have the yellow wire attached to it. (mine had just had the yellow wire shorted to earth to shut the buzzer up! the joys of second hand cars (sigh) )

White and blue is spare

[RW1 0]

(VR6 engine)

 

Three wires on the oil filter housing top. Two at front left & right are oil pressure switches. Back off-side is oil temp.

 

Oil pressure gauge should be screwed in to the near-side pressure switch position. It's a tight fit as the thread is interference fit and only just tightens down to being leak proof just before the sender contacts the top of the oil filter housing. Removed oil pressure switch sender wire goes to "WK". "G" to gauge "G" connection.

 

.

[STORM 2 0]

I tried to replace this - oil temp MFA sender-(as well) today but found it a bugger to access - do you have to remove the slam panel to get to it?

[RW1 0]

No, just have to have the right "short" or "odd" tools to get in. Granted it's VERY awkward. Skinned knuckles I seem to remember last time I was working in that area.

 

.