Oil pressure warning light?

[swain_cad]

I have a F80TLRA. The motor is mounted on a pontoon boat with a Yamaha remote. The oil light, pressure warning light, stays on all the time. Disconnected the oil pressure switch and checked continuity with the motor off and running. Had continuity with the motor off and infinite resistance with the motor running so the switch is working. The warning light even stays on with the sensor disconnected. The wire (pink and white) from the sensor goes through the CDI box. If I were going to wire a light for this pressure switch where would it tie into the motor harness? The warning light doesn't show up on any of the wiring diagrams.

[boscoe99]

I have a F80TLRA. The motor is mounted on a pontoon boat with a Yamaha remote. The oil light, pressure warning light, stays on all the time. Disconnected the oil pressure switch and checked continuity with the motor off and running. Had continuity with the motor off and infinite resistance with the motor running so the switch is working. The warning light even stays on with the sensor disconnected. The wire (pink and white) from the sensor goes through the CDI box. If I were going to wire a light for this pressure switch where would it tie into the motor harness? The warning light doesn't show up on any of the wiring diagrams.

Are you referring to a light on the dash panel or a light on a tachometer?

The warning light (presumably on a tachometer) has 12 volts applied when the key is on. The light is grounded in order to make it illuminate.

If you disconnect the 8 pin connector at the CDI box does the light illuminate when the key is turned to the ON position?

If you disconnect the trim/oil connector that has the pink/black wire and the pink/white wire connected to it, does the light still illuminate?

If the wire (pink/white to begin with) gets grounded anywhere from the CDI to the light then the light will illuminate.

[swain_cad]

Did as instructed. Disconnected 8 pin connector at CDI. Switched on ignition no light. Disconnected trim/oil connector, ignition on, no light. That should mean the wire to the motor is good, right? Trying to test wire from CDI to oil switch next. Any other ideas?

[swain_cad]

Disconnected wire from oil pressure switch. Disconnected 8 pin connector, checked pink white wire for continuity (good). Checked for ground it is not grounded.

Checked pink/white from 8 pin to trim/oil plug. Continuity good, also not grounded.

Reconnected 8 pin connector. Checked pink/white at trim/oil connector to ground. Doesn't test for continuity reads 600 ohms.

Does this mean I have a bad cdi? Just replaced the old one with a used one off eBay. Wouldn't shut off before, and idled poorly. Same problem with oil light. New CDI fixed other issues.

[boscoe99]

I would disconnect all of the devices that lead to the 8 pin connector. I would then check each of the 8 wires individually to ensure that none have continuity to any of the other wires.

I would then inspect the pin/socket on the CDI itself for the pink/white wire that provides the ground to the oil pressure warning light. With the key in the on position. There should be no ground output.

CDI's are normally very very reliable. Strange for you to be having multiple issues. What is the history on this motor?

[swain_cad]

History. Bought used boat. Don't have much prior info. CDI was bad wouldn't shut off. Had a skip at cold idle. Used CDI installed fixed those problems. Why on Earth is the oil pressure light ran through the CDI? Doesn't seem to affect the way it runs. Don't have any alarms. Will continue testing wiring on motor and post back.

[boscoe99]

History. Bought used boat. Don't have much prior info. CDI was bad wouldn't shut off. Had a skip at cold idle. Used CDI installed fixed those problems. Why on Earth is the oil pressure light ran through the CDI? Doesn't seem to affect the way it runs. Don't have any alarms. Will continue testing wiring on motor and post back.

If the CDI did not control the light then the light would be on any time the key is on and the pressure switch is closed due to low/no oil pressure. The CDI provides a delay in turning on the light.

[swain_cad]

Disconnected everything circled in diagram. Checked each wire at the 8 pin plug. None showed continuity with any other wire in the plug.

Checked resistance on pink/white pin at the CDI box with 8 pin plug removed. Didn't read continuity but had around 900 ohms resistance. Installed old CDI ran same test with same result. This should read infinite resistance right?

No physical damage is observed anywhere the motor appears to be in fine shape.

Still don't understand why it runs though the CDI. The pressure switch is normally closed. This would cause the light to be on when the motor is off. Once cranked oil pressure opens the switch and light goes off. What am I missing?

[swain_cad]

Disconnected the two pink and white wires from the 8 pin plug and spliced them together. Oil light works fine now. I haven't noticed any ill effects.