Low Oil Pressure sender Lpws4 Lister

[Plonk 5]

Hi folks. 

My Lister Lpws4 has a leaky low oil pressure sender. I think it must have been weeping for a while but I now think it is getting worse. The audible alarm stops when I start the engine, but I'm not sure if this alarm is also connected to the charge circuit. I don't appear to have a lighting up pressure  warning light on the warning light panel.

Before I change the sensor, I would like to find out what the 3 terminals are for. I am familiar with the  single wire type connected on car's.  3 terminals seems two too many! Are they, + (feed), buzzer and light? As the unit is leaky, I guess it may be the cause of the  warning lamp failure.

On a car it would be a simple case of touching the  sender +feed to earth, I fear if one of these wires is live, touching it to earth might blow something, as might connecting a live feed to one of the other terminals? 

I have no idea where I could get hold of a wiring diagram.

Thanks in anticipation,

Patrick.

[Boater Sam 630]

4 minutes ago, Plonk said:

Hi folks. 

My Lister Lpws4 has a leaky low oil pressure sender. I think it must have been weeping for a while but I now think it is getting worse. The audible alarm stops when I start the engine, but I'm not sure if this alarm is also connected to the charge circuit. I don't appear to have a lighting up pressure  warning light on the warning light panel.

Before I change the sensor, I would like to find out what the 3 terminals are for. I am familiar with the  single wire type connected on car's.  3 terminals seems two too many! Are they, + (feed), buzzer and light? As the unit is leaky, I guess it may be the cause of the  warning lamp failure.

On a car it would be a simple case of touching the  sender +feed to earth, I fear if one of these wires is live, touching it to earth might blow something, as might connecting a live feed to one of the other terminals? 

I have no idea where I could get hold of a wiring diagram.

Thanks in anticipation,

Patrick.

Electric pressure gauge and oil light?

[Alan de Enfield 8073]

23 minutes ago, Plonk said:

I have no idea where I could get hold of a wiring diagram.

Send me a PM with your email address and I'll send you the workshop manual (110 pages - should show what you want)

 

I cannot attach it here as it is a Pdf (which are not allowed to be attached)

Edited September 19, 2019 by Alan de Enfield

[WotEver 3163]

17 minutes ago, Boater Sam said:

Electric pressure gauge and oil light?

That’d be my guess. 

 

Plonk - do you have an oil pressure gauge?

[Plonk 5]

No guage, just buzzer and light.

[Plonk 5]

No guage, just buzzer and light. There is a big white control box in the engine comparment though!

The sender looks like a normal small low pressure warning sender

 I guess just simple contact switch inside.

[Plonk 5]

I will hopefully work out when Alan sends me the wiring diagram.

[Plonk 5]

Unfortunately the manual online only goes to page 109. Wiring is on page 129. 

On thinking about it,. I would guess that the wiring might  be : 12v feed, buzzer out 12v no pressure,  light out 12 v pressure. ? I will hopefully figure it out when the new switch comes.

Edited September 20, 2019 by Plonk

[jonathanA 95]

It’s a changeover type switch (spdt) touch the non black wire to earth to check wiring / bulb 

 

sounds like bulb has gone if buzzer working. It has no impact on charging unless none of the lights are working which is a different issue I would think 

 

Big white box isn’t relevant although check the two circuit breakers on the top of the box one is for the stop solenoid and I think t’other supplies the instruments. 

[Alan de Enfield 8073]

23 hours ago, Plonk said:

Unfortunately the manual online only goes to page 109. Wiring is on page 129. 

On thinking about it,. I would guess that the wiring might  be : 12v feed, buzzer out 12v no pressure,  light out 12 v pressure. ? I will hopefully figure it out when the new switch comes.

oops -sorry I'll email that section.

The 'most important one & I didn't send it.

 

 

[Alan de Enfield 8073]

I just tried emailing it and got an 'expired error'

 

Ok - got it to work this time 

46 pages - Industrial engines first, then scroll down for Marine engines.

 

Alan

Edited September 21, 2019 by Alan de Enfield