Topic: Oil pressure light

[britman]

I have been chasing wiring all day and finally got everything up and hooked up on my aftermarket handlebar switches and wiring harness except my oil pressure light.  I have 12 volts coming up from the sending unit but no dash light when you turn the key.  Not but two wires blue/red and black and they are in the correct position.  It looks like the outside shell of the bulb holder gets juice and will light up the test light but not center where the bulb rests.  I have tested the bulb holder by attaching the blue/red wire to neg and black to positive on a battery and it will function.  It was working perfectly prior to hooking the complete harness up. I am going to walk away for the night and hopefully tomorrow will  produce the cure unless one of you gentlemen can tell me what I am missing here. Would a bad sending unit still send juice up through the harness?  Everything else in the dash lights work-high low beam-turn signal light-and neutral.

[Bodi]

Having some trouble understanding what you've done.
The pressure switch grounds on low pressure. So one side of the bulb should get +12v with key on, with its other side connected to the screw on the pressure switch.
Sorry but your description isn't clear on what you have the lamp connected as.
If it is as above, the sender is probably bad. Touching the wire on the sender to the case (ground) should light the warning lamp

[BenelliSEI]

You’ve got it backwards. The sender is the ground to the outside of the bulb socket. The centre pin in the socket should have power (+) when the key is on. As soon as the oil pressure comes up, the sender switch opens. No ground = No lamp.

[britman]

Ok here is where I am this morning.  I removed the rubber cover from the sending unit to access the terminal.  There is close to 12 volts on the wire, the current runs through the harness to connection at the blue/red wire.  The black wire from the bulb has power, checked and double checked, still no light.  When I run a ground wire to the sending terminal, I have a dash light so I am assuming I have a bad sending unit that is not grounding.  There can't be anything else I can think of.  They are cheap, so a new one is on the way. Again for you electrical gurus, am I close???

[BenelliSEI]

You got it. Faulty sending unit. Attach your test light to the positive terminal on the battery. Touching the probe end to the screw on top of the sending unit should show a light (the switch is closed and passes the ground through it). When you fire up the engine, the switch opens and no more ground and dash light (or test light) goes off.

Sometimes you can blow brake kleen, using the straw, up into the switch and bang some crud out and free them up. For what they cost, replace it.

[britman]

New one is on the way.  In the meantime, I have the aftermarket wiring harness and new right and left handlebar switches and not a damn one has the same style connector.  While I am waiting I am going to spend some time on each connection making sure they are secure. When the birds nest goes back in I don't want any problems.