Stupid question about oil pressure sender - 88 4Runner 3.0

Apr 27, 2017
Tacoma, WA
The oil pressure gauge on my SR5 is very erratic. It usually sits at zero...sometimes it will bump up to "normal" and then slowly creep back down to zero and just stay there. It's done that for a while and no ill effects that I can tell.

I am thinking about replacing the sender with an OEM sender, but from what I can tell there is no cable to connect to? How does it "send" the signal back to the gauge? On a past 4Runner, I replaced the temp sensor and that has a little spade fitting. Just not sure about this one.

I could diagnose it with a mechanical gauge but then I would be spending $30-$50 for a gauge that might tell me the pressure is fine and the sender is the problem.

Feb 9, 2004
Cool Comfy AZ
Yeah what he said. Look for a yellow wire with a black stripe. It should have a connector that slides onto that brass-colored round piece at the top in your picture. Probably white plastic. It's grounded through the sender.

BTW I'm no expert I looked it up on Auto Zone's website. Create a free account and go to "Repair Guides" look though the menus and you'll find the Fig. 71: Wiring diagram-1988 Pick-up and 4Runner

Good luck


Oct 7, 2003
Too far north. Too far east.
There are two flavors. Gauge, and idiot light. Do not use idiot light sender with a gauge. There should be a short pigtail off the harness to the sender. It just clips onto a button on the sender.
Last edited:
Dec 6, 2021
I assume you've already solved your problem, but if not, here is my take on this:
On my 1HZ the oil pressure sender looks very similar to the one you show in the add.
The only difference is that mine has two connection points, one male 6.3 mm spade type and the button like (small mashroom ) on the top of the sending unit.
In the add picture only the "mashroom" type connector is visible, so probably it gets the ground from the engine block.
Any how, The small button like connector on the head of the sending unit is supossed to be connected to a female 6.3mm spade type connector, usually with one side of the insullation open, as it attaches perpendicular to the sending unit main axis.
I have attached a picture of my sending unit and one for ean example of the type of connection for the top connector of the sending unit

Oil sending unit connector type.JPG

Oil pressure sending unit.jpeg

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