jakebrake86 Posted February 21, 2015 Share Posted February 21, 2015 I have a '96 RD688S with a manual E7 350. The warning light that goes off for low oil pressure, low water level, or high water temperature has started going off for no apparent reason, and it usually only stays on for a few minutes before going back off. I unplugged the low water sensor in the reservoir, to no avail. I replaced the high water Kysor alarmastat on the back of the water manifold. Still going off. I'm guessing the oil pressure sending unit must be going out. My question is, does the light get its electrical feed from the oil pressure gauge itself, or is there an electronic sending unit on the motor somewhere? The gauge is manual and fed by an oil line off the oil filter base. 1 Quote Jake Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/ Share on other sites More sharing options...
gearhead204 Posted February 21, 2015 Share Posted February 21, 2015 jake as far as I know its a simple system, it all works off of ground so if any component can ground the lite will come on! most likely its the coolant level sensor or a shorted wire telling the light to illuminate . Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-279983 Share on other sites More sharing options...
Solution turckster Posted March 3, 2015 Solution Share Posted March 3, 2015 The oil psi sender is behind the speedo/tach in an aluminum block. The #4 line off the filter base runs through the cowl/firewall to this block then to the gauge. BTW, unplugging the coolant level sensor will activate the alarm. When the coolant resivior/tank is full the coolant completes the circuit, by unplugging it you open the circuit causing the kysor module to think the coolant is low. More often that not the coolant level sensor is the problem, scale builds on the coolant probe insulating it. Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-281322 Share on other sites More sharing options...
MACKS Posted March 3, 2015 Share Posted March 3, 2015 Is this the engine shut down light that your talking about,I have the same problem on my 96 cl,If you figure it out please let me know. Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-281331 Share on other sites More sharing options...
jakebrake86 Posted March 4, 2015 Author Share Posted March 4, 2015 Yes it is the shutdown light. Thank you, Turckster. That explains a lot. I assumed if the low coolant sensor was unplugged, the light would go off. I'll check that next and let y'all know if it fixed it. Thanks again! Quote Jake Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-281403 Share on other sites More sharing options...
jakebrake86 Posted March 16, 2015 Author Share Posted March 16, 2015 The oil psi sender is behind the speedo/tach in an aluminum block. The #4 line off the filter base runs through the cowl/firewall to this block then to the gauge. BTW, unplugging the coolant level sensor will activate the alarm. When the coolant resivior/tank is full the coolant completes the circuit, by unplugging it you open the circuit causing the kysor module to think the coolant is low. More often that not the coolant level sensor is the problem, scale builds on the coolant probe insulating it.Turckster, you were right. The low water sensor in the reservoir fixed it. After you told me that, I unplugged it and jumped it with a wire, and the light went off. Do I replaced it and everything is working like it should now. Thank you very much. MACKS, try unplugging yours and jumping it. I bet it will solve your problems, too. Quote Jake Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-282745 Share on other sites More sharing options...
Sehka77 Posted February 24, 2021 Share Posted February 24, 2021 On 3/15/2015 at 6:42 PM, jakebrake86 said: Turckster, you were right. The low water sensor in the reservoir fixed it. After you told me that, I unplugged it and jumped it with a wire, and the light went off. Do I replaced it and everything is working like it should now. Thank you very much. MACKS, try unplugging yours and jumping it. I bet it will solve your problems, too. What do you mean by jumping it with wire ? Might have same issue trying see how I can test it Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-469536 Share on other sites More sharing options...
fjh Posted February 24, 2021 Share Posted February 24, 2021 9 hours ago, Sehka77 said: What do you mean by jumping it with wire ? Might have same issue trying see how I can test it Bro That was the test! a paper clip! Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-469541 Share on other sites More sharing options...
Sehka77 Posted March 3, 2021 Share Posted March 3, 2021 On 2/24/2021 at 6:40 AM, fjh said: Bro That was the test! a paper clip! Thanks 👍 Quote Link to comment https://www.bigmacktrucks.com/topic/39013-warning-light-working-erratically-on-96-rd/#findComment-469858 Share on other sites More sharing options...
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