Oil pressure light keeps flickering. What’s up?

[m1garand_man]

My oil pressure light on my m1009 is now flickering. I went through some deep puddles today and the whole truck got wet and the light came on and then started to flicker on an off. It’s the first time since I've owned the truck that this has happened. I have 20k miles over two years and plenty of really wet and muddy off reading with no issues with the light before. I'm thinking its a short but I cant tell by the wiring diagrams where the possibility of a short could come from since it looks like the oil pressure sensor is just a switch with a single wire going directly to the oil pressure light. I've also had my alternator lights do this in the past too all though they haven’t done it in a while.

What is your take on this? Has this ever happened to you? Is it a short or is the light coming on for real? Also where would the short most likely be?

 

[lavarok]

No way to tell remotely. Put a mechanical gauge on it to check, if pressure is ok then troubleshoot the circuit or leave it mechanical.

One day I want to get around to replacing all the idiot lights with mechanical gauges. I hate idiot lights!!!

 

[dstang97]

No way to tell remotely. Put a mechanical gauge on it to check, if pressure is ok then troubleshoot the circuit or leave it mechanical.

One day I want to get around to replacing all the idiot lights with mechanical gauges. I hate idiot lights!!!

I hear ya, but you can just add them instead of cutting up the oem cluster. Really only need water and oil.

 

[lavarok]

I was not planning to cut up the cluster. Remote mount under the dash or a fabbed a-pillar mount would be used.

 

[top_prop]

Do it!... then post pics here! I have both water and Oil P on my list of mods... call me crazy, but I just don't like idiot lights either... they don't come on 'till its too late... gauges will tell you the story!

 

[mistaken1]

Doesn't the oil pressure sensor just ground one side of the light?

 

[Warthog]

Doesn't the oil pressure sensor just ground one side of the light?

The switch does provide the ground for the circuit. It is normaly closed (no pressure-light on) and opens around 7psi. (pressure-light off)

If the wire to the switch is grounding somewhere (I would guess the engine compartment) the light would flicker. It may be a bad switch also.

To send safe and make sure the engine isn't having issues I would install a mechnical gauge to test the pressure.

I was trying to figure out why a M1009 oil light was staying on so I installed a gauge along with the light and also a new switch ( Oreilly's - S397). I don't know if I will leave it in place or not.

Here are some pics of the gauge install. The brass fittings where standard SAE that I bought from ACE Hardware. I think they where 3/16". I took the switch in and dug thru the bins.