1986 2GM20F Can someone give me some ideas as to why, all of a sudden, when I turn the key to the "on" position, the oil pressure alarm doesn't sound nor the light come on? I'm pretty sure the sending unit is designed as normally closed, and it is grounded properly. When I throw the test switch, the alarm sounds and only the "charge" light comes on. Trying to help a friend. Any help very much appreciated!
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So providing the circuits with power
results in no oil pressure switch circuit. sounds like you diagnosed it correctly yourself. The circuit is either not getting power or is not grounding out on low pressure. with the ignition on and engine off, disconnect the sending unit terminal and test for voltage. You should see 12ish volts. Then check to make sure that the sending unit does not have resistance. If you have 12 volts on the wire and no resistance then you have demon infestation and I can't help If you don't have 12 volts on the wire trace back to find out where the voltage does show 12 volts and there is your problem. If the unit has more that 100 ohms or so (should be almost 0 really) the unit is bad or not grounded correctly.
results in no oil pressure switch circuit. sounds like you diagnosed it correctly yourself. The circuit is either not getting power or is not grounding out on low pressure. with the ignition on and engine off, disconnect the sending unit terminal and test for voltage. You should see 12ish volts. Then check to make sure that the sending unit does not have resistance. If you have 12 volts on the wire and no resistance then you have demon infestation and I can't help If you don't have 12 volts on the wire trace back to find out where the voltage does show 12 volts and there is your problem. If the unit has more that 100 ohms or so (should be almost 0 really) the unit is bad or not grounded correctly.
Yanmar oil alarm - possible reason
Hi Gary, We have a 1983 Yanmar 1GM engine and experienced a similar problem. I will try to explain what happened even though I'm not sure I'm using the correct terms to describe the components involved. The ignition key inserts into a cylinder that has wires attached to the back of it to make electrical contact with the starter,etc. It is held into place against the sheet metal panel that all the instruments are mounted on by a beezel ring that screws to threads on the cylinder. In our case, it had loosen to the point that it was not making adequate contact but after we tighten the beezel ring so that it once again made contact with the instrument panel plate the oil pressure alarm would sound as it should. To check this, just insert the key into the ignition cylinder and see if it is loose. If it is, this may the answer to your problem. Good luck, Lamar
Hi Gary, We have a 1983 Yanmar 1GM engine and experienced a similar problem. I will try to explain what happened even though I'm not sure I'm using the correct terms to describe the components involved. The ignition key inserts into a cylinder that has wires attached to the back of it to make electrical contact with the starter,etc. It is held into place against the sheet metal panel that all the instruments are mounted on by a beezel ring that screws to threads on the cylinder. In our case, it had loosen to the point that it was not making adequate contact but after we tighten the beezel ring so that it once again made contact with the instrument panel plate the oil pressure alarm would sound as it should. To check this, just insert the key into the ignition cylinder and see if it is loose. If it is, this may the answer to your problem. Good luck, Lamar
Last season...
...I had a similar problem where my tach and bell didn't work (1988 L37 - 3HM35F). Turn out to be a blown 30a fuse that was in a line and dedicated fuse holder. It started when I moved the noise suppressor/air filter cone ans the bail shorted against the starter. Maybe...just maybe...
...I had a similar problem where my tach and bell didn't work (1988 L37 - 3HM35F). Turn out to be a blown 30a fuse that was in a line and dedicated fuse holder. It started when I moved the noise suppressor/air filter cone ans the bail shorted against the starter. Maybe...just maybe...
Same thing, different method
Disconnect the wire from the oil pressure sending unit. Turn the switch on. Ground the wire that you disconnected from the switch. If the light comes on/buzzer goes off, the switch is bad. If not, then check the voltage at the wire, and start backtracking till you find where it looses it's 12 volts.
Disconnect the wire from the oil pressure sending unit. Turn the switch on. Ground the wire that you disconnected from the switch. If the light comes on/buzzer goes off, the switch is bad. If not, then check the voltage at the wire, and start backtracking till you find where it looses it's 12 volts.
I have a similar problem thats switch related.
There is a dead spot in my switch that won't activate the alarm that I haven't yet fixed, so I have to turn the key a little more or less and off the alarm goes.
There is a dead spot in my switch that won't activate the alarm that I haven't yet fixed, so I have to turn the key a little more or less and off the alarm goes.
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