Checking Oil Pressure Sending Unit L175/1500

[billrigsby]

I have looked through all my books, can not find a way to check the
Oil Pressure sending unit?

My oil light is either on or flickering, but gauge shows good pressure?

Tempted to just order one, but I hate throwing parts at something.

 

[Dave_eng]

Now your dilemma is which do you trust, the gauge or the light. Either one could be off. A second gauge would revel the truth. You could remove the oil light switch and build a pressure test device to allow you to adjust the pressure the switch sees and at what point the contacts open or close. I have made such testers with a bicycle pump but you will spend time just coming up with the fittings to connect everything together.

I would clean all electrical contacts in the oil light circuit first.

Dave M7040

 

[mattwithcats]

Sender is just a pressure switch, it closes with no or low pressure, and opens with sufficient.

Short the sender wire to ground, light should come on.

Ohm the sender, you should get infinity when you have pressure, and zero with none...

 

[billrigsby]

Now your dilemma is which do you trust, the gauge or the light. Either one could be off.
A second gauge would revel the truth.

Well, I put the gauge in because I do not trust lights, and want real time readings.
I may get a second one to confirm, have Amp, Volt, Vacuum, but no extra Oil lying around.

Sender is just a pressure switch, it closes with no or low pressure, and opens with sufficient.

In the past others I have dealt with were variable resistors, so I "assumed" and was looking for specs.
If it is just a switch, what would explain the flickering? at various RPMs

I did just order one as they are only $13, shipped to my door (at least the box down on the main road),
if we were talking $100+ I would not have gone that route

 

[North Idaho Wolfman]

It's a bad pressure switch, they do stupid things like that when they go out.

 

[mattwithcats]

I believe the fitting on the oil sensor is 1-27 BSPT...
Subaru uses the same...
http://www.lmaautoparts.com/products/Gauges___Gauge_Fittings/

An inexpensive gauge set, note that the size is not 52 mm, 2 1/8, but 1 7/8..

Auto Meter 2391 Autogage Electric Mini Oil/Volt/Water Gauge with Black Console https://www.amazon.com/dp/B00062YW06/ref=cm_sw_r_cp_tai_-xEMzb7ZBX349

 

[billrigsby]

It's a bad pressure switch, they do stupid things like that when they go out.

Yep, that's my opinion.
Had to go into town today, which I hate doing on a Saturday or a Sunday,
Or for that matter Monday through Friday, but when your honey is getting a ride half way from DIA, you meet someone in the Springs!!

Any whooz, needless to say I picked up another oil pressure gauge and......
almost identical, plus or minus 3 lb.
I recall someone actually attaching a gauge to the fitting on the oil filter it was either Darren or Coach, but I could not find the proper fitting to do that adaptation.

So I ordered a new sending unit, needless to say I'm just trying to avoid that "C - P" word.

 

[billrigsby]

New sending unit fixed the problem,
got one from Kumar Bros. $12.99 / free shipping.

I wish it was the standard size, so my sending unit socket would have fit,
but, they had to make it different, first one I have seen that did not have
the standard dimensions.