Replace 88 GL Oil pressure sending unit

[YnotDIY]

Hey everyone in the process of replacing the oil pressure sending unit on my 88 GL 4x4, the gauge hasn't worked since I got the car and it's stressing me out a little. Anyway, I have a couple of questions. Planning to post this in the fix it section when everything is finished so others can benefit as well.

 

Is it necessary to drain the oil prior to pulling the sending unit?

It looks like the one on the car now is unplugged from the female spade and I'm not sure where to find the wire...ideas?

There is a part directly next to the sending unit that is plugged in with a spade can I just move it over to the sending unit (doubt it.....)

What's the "normal" gauge reading for oil when this thing is fixed?

 

Thanks everyone any advise is appreciated. After this it's the fuel filter.

 

[DaveT]

The oil pressure sending unit is bigger than a typical oil light pressure switch. There are ports for both on the oil pump housing. There is 1 wire that comes out of the engine harness kind of behind the power steering pump. Goes past the dipstick, then strait down to the sensor.

[DaveT]

The sensors are easier to see from underneath. May have to take the skid plate off. I've left mine off for years now, as I don't do crazy off road stuff.

 

If your instrument cluster has a gauge, it should just work.

[TomRhere]

You have both in those pics.

 

The wire is currently plug onto the Oil Light Switch.

 

Unplug the wire and move it over to the larger Oil Pressure Sending Unit.

 

Gauge should read after that.

 

The Factory gauges aren't real accurate. You will see it show "0" pressure at idle on a fully warmed engine. Totally normal, and stated so in the Owners Manual and the FSM

[YnotDIY]

This all sounds good to me. There should probably be separate wires for the sensor light and the sending unit correct? I'm only seeing one wire and it's attached to the oil light switch. Should the other follow that wires path or does it come from a different location? Any idea how to rig one to the sending unit if I can't find it? Thanks everyone this has already been a big help. Oh and is it necessary to drain oil pre removal of the sending unit?

[BEECHBM69]

This all sounds good to me. There should probably be separate wires for the sensor light and the sending unit correct? I'm only seeing one wire and it's attached to the oil light switch. Should the other follow that wires path or does it come from a different location? Any idea how to rig one to the sending unit if I can't find it? Thanks everyone this has already been a big help. Oh and is it necessary to drain oil pre removal of the sending unit?

 

The wire plugged into the switch is the one that should be connected to the sender. There is a philips screw on the end of the sensor that normally has a ring connector on one end, and a male spade connector on the other. The spade connector is what would go in the female spade with the cover over it. (I'm not near my car right now, the male female part might be backwards, but you should get the gist of what is supposed to be happening.)

 

Dan

[DaveT]

There is only 1 wire, because the normal situation is either pressure gauge OR oil light, not both.

 

There is no reason to drain the oil pan, the sender is in the output pressure side of the pump.  The oil in the pan cannot go uphill through a positive displacement pump to get out.

 

Some oil in the channel will come out, but it's not a lot, and pretty much no way to avoid that.

[YnotDIY]

Alright thanks. Taking off the skid plate and doing the swap tonight. Of course it's snowing here again and I don't have a garage, but luckily it's not to cold. I'll update when everything is finished. Thanks again for the help.