Jump to content
dustyxbla

Oil pressure light. Help!

Recommended Posts

On 4/6/2019 at 7:29 AM, Ozzie said:

I’ve been having a similar problem on my 1979 CB750L.  I changed all the lights to led’s, but my oil pressure light stays on.  I bought a new oil pressure switch, and I have enough oil and oil pressure.  After reading this forum, I think I need a resistor, but I’m not sure where exactly.  Do I need to put one by the stop light warning unit, down by the oil pressure switch, or in line with the taillights?  Any help would be great!

What happens when you manually operate the switch or just ground out the wire? 

Share this post


Link to post
Share on other sites

The oil pressure light still stays on when the bike is running, and I manually ground the wire going to the oil pressure switch.

Share this post


Link to post
Share on other sites

How do you know you have oil pressure? Did you check it with a calibrated gauge?

Share this post


Link to post
Share on other sites
4 hours ago, Ozzie said:

The oil pressure light still stays on when the bike is running, and I manually ground the wire going to the oil pressure switch.

Switch works by breaking ground to shut off light. Remove switch from equation, if light remains on you have a short to ground somewhere in the wire that goes from switch to gauge cluster. Easy fix, run new wire. If light goes off, you either have low oil pressure or a shot switch, or one that works by the opposite principal as the one you need. Easy check, hook test light or VOM  to switch body and wire terninal, see if its normally open or normally closed. Apply pressure where the oil would usually go, see if switch opens or closes. Start motor with switch removed to confirm oil pressure lmfao.

Share this post


Link to post
Share on other sites

honda wires up stuff really strange from the few I've worked on.  the brake light circuit on this 05 rebel my buddy bought is wired through all kinds of shit that doesn't do anything with the brake light.  

they have some crazy electrical engineers.

Share this post


Link to post
Share on other sites
14 hours ago, Pauly said:

How do you know you have oil pressure? Did you check it with a calibrated gauge?

I removed the oil pressure switch and turned the engine over resulting in oil coming out of that spot.  That should mean I have adequate pressure.  Correct?

Share this post


Link to post
Share on other sites
10 hours ago, Gixxus Christ! said:

Switch works by breaking ground to shut off light. Remove switch from equation, if light remains on you have a short to ground somewhere in the wire that goes from switch to gauge cluster. Easy fix, run new wire. If light goes off, you either have low oil pressure or a shot switch, or one that works by the opposite principal as the one you need. Easy check, hook test light or VOM  to switch body and wire terninal, see if its normally open or normally closed. Apply pressure where the oil would usually go, see if switch opens or closes. Start motor with switch removed to confirm oil pressure lmfao.

I’m not sure it’s a ground shorting out elsewhere because the oil pressure indicator light has a specific ground (red/blue wire), and I’ve traced that wire from the indicator down to the switch, and everything appears to be fine.

Share this post


Link to post
Share on other sites
5 hours ago, Ozzie said:

I removed the oil pressure switch and turned the engine over resulting in oil coming out of that spot.  That should mean I have adequate pressure.  Correct?

It means you have some pressure. The light is not necessarily for "no pressure". It is a low pressure indicator warning. You probably have adequate pressure, but as of right now you have no idea. 

Share this post


Link to post
Share on other sites

The light wasn’t on when I had my my old gauges, and the bike sounds fine while running (no clunking or rattling noises) so I’m thinking it has something to do with the new led’s I installed.  I’ve also checked the oil levels several times after running the bike, and they were sufficient.

Share this post


Link to post
Share on other sites
8 hours ago, Ozzie said:

I’m not sure it’s a ground shorting out elsewhere because the oil pressure indicator light has a specific ground (red/blue wire), and I’ve traced that wire from the indicator down to the switch, and everything appears to be fine.

Oil pressure causes the switch to break ground contact to the bulb. Read that again. If you have a path to ground at the bulb, the switch is closed or you have a short. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×