Audi VDO guage fitment (again)

[ozegti]

collar = small bit of plastic just bellow the connector.
mfa oil temp = white
water temp = black
audi vdo sender = blue

just swap the small sensor over, they are the same shape, just have a different colour on the plastic collar

right, So i've swapped the sensors over, but what do I do about the twin sender? What wires go to where? Is it a case of one goes to oil temp the other to oil pressure? If so, how do I know which is which?

The +/- go to the gauge (+= +ve and III=-'ve)
G goes to the gauges???

[rubjonny]

Oh ok, didnt know that!
if its an audi sensor G is for the gauge, WK is for the old oil warning wire

[Ben Lessani]

Yeah, it took a bit of convincing from me to the guy I was getting the guage off too - had a debate for 5 minutes. He just kept saying, how is 1/8th of an inch 10mm - oh well

There's oodles of guides for these gauges, how is there any confusion?



The audi oil pressure gauge needs its own specific sender. If its a 10bar gauge, it needs a 10bar sender. You can't use the exisiting one on the engine as this is for the low pressure buzzer/warning light and is incompatible. However, you get the bonus of a twin pole pressure sender from the Audi which has both the connector for the guage (G) and for the dash (WK).



The oil temp is the same story, if you want to maintain the MFA readout on your dash, then you need to get a T piece. As the oil temp sensor from the Audi isn't twin pole - it means that you have to get a 1/8 NPT (M10 x 1) T piece, then screw your original MFA sensor in, and the Audi gauge sensor in.

Then you just route the wires back to the cabin. The +ve and -ve can be taken off a relay from the IGN/GND on the fusebox and the blue wire from the cig lighter as a trigger.

The theory is that almost any sender will work with any gauge as its all just based on resistance - so if you buy a universal sender off ebay that can read up to 10 bar - theory says it should work with any 5 bar gauge, or infact anything up to 10 bar. I'm not speaking from personal experience, however.

[rubjonny]

different sensors return different resistances though, i.e. VW 0-180 and Audi 0-180 temp sensors return different resistances.  pretty sure the same is true for the 0-5 and 0-10 bar senders?

[ozegti]

right. Got it wired up I think, though the white collar snapped the head off the sensor!

Which is the warning wire?

I ran 2 wires from the gauges to the twin sender and now reads about 70deg for oil temp and Off the scale for the oil pressure.If I swap the wires around I get no temp but fluctuating oil pressure according to revs but stays roughly 3.5-4bar.

Also went to ECP and tried to find the twin wired plug at the back of the water housing, but no joy. Said it doesn't exist for my engine.

What's the Audi blue sensor for?

[rubjonny]

the warning wires are the yellow (1.8bar warning) and blue (0.3bar warning)
the audi blue sensor is for the audi VDO oil temp gauge, VW sensors are not the correct rating.

[ozegti]

Poo. I need the blue sensor then. (Where do I put this on the engine?)

Which wires are for what? and what goes to where?

[rubjonny]

just re-read your other post.  The VDO twin sender is pressure only as in you take out one of the original pressure warning switches, and fit the VDO in its place. then plug the original pressure wire to the WK terminal and the pressure gauge to the G terminal.
The audi oil temp gauge needs a completly different sensor, the blue one i mentioned above

oil temp can go anywhere really, as long as its in an oil chanel.

[ozegti]

I meant the warning wires. Sorry.

Which wire is the pressure wire? Is it the upright one with the white sleeve?

[rubjonny]

the chunkier ones with the yellow and blue wire, big rubber boot over the spade