osugasman

OK. I just changed the bad oil pressure sender in my car. The "white" wire was going to the right which was labelled WK. The other was red. I was surprised on installing the new one that the "white" sensor was now only fitting on the left side (not the WK side) due to the thin/thick connectors only going one way. After installing the SAI pump (yeah, I couldn't figure this out earlier), I realized that the white wire probably should be going to the WK side. After consulting the repair manual, I confirmed the "white" striped wire should be oging to the WK side, not the other side. I also confirmed that mine was wrong since it appears the parts company f***ed it up at the factory. Just looking for confirmation that I need to strip it apart and repeat an hours worth of labor since (VDO/URO??) has no quality control. Here is the photo confirming my white striped wire is NOT going to the WK side and here also is a screen shot of the wiring diagram. Note: the second was $30 vs $100 for OEM.

So just to confirm, I need to rewire the sender so that the correct width connector is on each side.

osugasman

OK. So no opinions so far. Maybe I should rephrase the question a little bit. What should I expect to see when turning the key to accessory but not actually starting the car for the oil pressure reading? In the past my oil pressure would ping at 5 Bar and never come down from there which is apparently typical of a bad sender unit.

4X4SCHE

The narrow terminal should be on the G terminal and will fit the Red/Green wire.

FrenchToast

Seems unclear about your sender, but I would only use OEM manufacturer for the sender.

Take care!

osugasman

Thanks. I'll switch the wide and narrow tabs around today. Great QC from URO parts, if I had had the varioram all buttoned up, it would have been a colossal waste of time.

osugasman

Ok, this is getting a little ridiculous. I switched the wide and narrow tabs around so that the Gr/Wh wire is going to WK side and the Gr/Re wire is going to the R side (per wiring diagram in shop manual.) Did full reinstall and test drove car. Oil pressure gauge pinging on +5 Bar from accessory right on through to actual driving. (Good news is that I seem to have got all the vacuum lines back together and didn't have any extra connectors or bolts). Weird twist is this, with the original backwards connections from factory, I was reading ZERO Bar on pressure gauge when ignition switched to accessory. Couldn't start the car with everything still disconnected. Upon "fixing" the wiring and connectors to be consistent with the factory manual, I got +5 bar in all modes, including accessory. Could the URO OEM copy unit have been designed different from factory OEM??? That wouldn't make any sense. Guess I will try again next Winter when an engine drop is on the schedule for some bigger projects....Time for a

IXLR8

You have an open circuit or a resistance greater than 200 ohms.

This is what the resistance of the sensor should measure. Roughly 80 to 100 ohms at idle and about 180 ohms at cruise RPM.

jan the man

Put non oem sender in over the winter, at idle it would drop to zero, when driving it would pin at 5 bar. switched leads around as they where not clearly marked, then is would pin at 5 and stay there. Non oem sender had bigger hole in bottom then original. Put original back in for now eventhough at idle it drops to zero.Has been like that for years no problem with car. OEM next winter.

osugasman

Alex,

Is this a wiring specific connection or could you just have Gr/Wh on one lead and Gr/Re on the other and be ok?

--Brian

IXLR8

They have to be connected to the correct sensor lugs.

The oil pressure sensor/pressure switch does two things: operate your oil pressure gauge and cause the oil pressure indicator light to illuminate.

GN/RD goes to the oil pressure gauge. If you hook up a 100 ohm resistor to this lead and ground the resistor, your gauge should read 2.5 bar.

GN/WT goes to the Central Informer.

On the sensor, the WK should short to ground with the engine off and likewise the G should be a very low resistance (I'm thinking ~10 ohms). Maybe if a fellow RLer has a known functioning sensor on hand, they can confirm.

I never had one in my hand to test. This info is based on the electrical wiring diagram.

osugasman

Thanks, Alex. Jan: next time I will definitely order OEM after all this nonsense.

vincer77

If the sensor is strictly a variable resistor, then does it matter which wire goes where?

IXLR8

One contact is a variable resistor, the other contact is a switch. At least according to the wiring diagrams.