Nissan LD6-78 pre-heat problem

[Randall]

My ‘86 Albin 27 FC has a Nissan LD6-78 diesel. The pre-heat light does not turn off after engine start. For approx. the last 200 hrs. Of operation it takes three tries to get engine started and the light and buzzer always turned off. Sorry to bother you folks but I need help on where to start. The Nissan forum or Hull Truth were no help. Wiring is dry and solid. Thanks in advance. Randall

1986 Albin 27 FC. “Meridian”
North Fort Myers, Fl

[TorreyWP]

I have the same engine Randall but I do not have a preheat light so forgive my initial questions. Mine is a 1985.

How do you activate the glow plugs to pre heat? Do you have a separate button you hold or turn the key in the opposite direction?

How did the light operate prior to this issue? When you activate the glow plugs/preheat circuit a light is lit on your dash panel to indicate the circuit has power?

The buzzer I am familiar with, that indicates overheat or loss of oil pressure so once things going on start up, that goes off. If you are having trouble starting from cold, you could have an issue with the glow plug/preheat circuit and that can be diagnosed pretty easily with a digital multimeter. I can help, just want to be sure I understand how the light works in relation to the system.

[Randall]

Thanks Torrey, Turning ignition key to the left initiates pre-heat and adjacent red light glows. Turn key to right is ignition and red light stays on and buzzer is activated usually for about 5 seconds and both light and buzzer go out. This engine normally takes three tries before starting and both buzzer and light go out. Engine runs smooth and to temperature (150 degree) with good oil pressure. A picture enclosed if it works this time. Randall

[davem554]

On my 86 with the ld28 the red light is for the buzzer for oil pressure. You minght check both sensors on the rear of the block and near the thermostat housing..
There is also a device I’ve seen that shuts down the engine with overheating.
Hope this helps , the LD 28 is a great engine IMO.
Dave Marks

[Randall]

Bullseye Dave and Torrey, it was one of the water temp. sensors near the thermo. housing. (lower of the two}. Now the hunt for a replacement begins. Many thanks to you both. Randall