Oil Warning Light Not Working

[robc76]

Morning folks.

I have recently awoken my 1150GS from a 3 year snooze, got it MOT'd and it still rides perfectly. However, the oil pressure warning light does not work with ignition on and engine off.

What I've checked so far:

Swapped the bulb for a known good one. No change.
Checked the voltage in the bulb holder with ignition on and engine off. 9.5 volts. Bulb still not illuminated.
Checked voltage of main beam bulb holder with ignition on and engine off. 9.5 volts. Bulb illuminated when main beam switch on.

It does seem odd that the contacts in the bulb holder are registering 9.5 volts without the bulb lighting up.

I've not yet traced the wiring to check for visible faults (I will when the tank isn't full of fuel). Before I do, I would like to ask the forum if this could just be a faulty pressure sensor?

Thoughts?

Regards

RobC

 

[robc76]

By the way, I checked the voltage of the main beam bulb holder just for a comparison.

 

[Pete.]

Pull the wire off the switch and ground it to the engine. If the bulb lights then the switch is toast.

 

[robc76]

Thanks. Presumably, that is with the ignition turned on?

RobC (Electrical numpty)

 

[DrFarkoff]

Yes

Ign on

Ground the connection to exhaust or the big nut of the pressure switch or add a length of cable and ground it higher up so you can see

 

[robc76]

Thanks fellas. I'll give it a go and report back.

RobC

 

[robc76]

Update: I pulled the spade connector from the oil pressure switch and the wire fell away so corrosion had crept in. I fitted and new connector and cleaned up the terminal. With the connection made, the oil light remains off. When grounded to bike, the oil pressure light came on meaning the wiring is good and the switch is faulty. A new one will be ordered tomorrow.

Thanks for pointing me in the right direction chaps.

Regards

RobC

 

[jefformston]

Morning folks.

I have recently awoken my 1150GS from a 3 year snooze, got it MOT'd and it still rides perfectly. However, the oil pressure warning light does not work with ignition on and engine off.

What I've checked so far:

Swapped the bulb for a known good one. No change.
Checked the voltage in the bulb holder with ignition on and engine off. 9.5 volts. Bulb still not illuminated.
Checked voltage of main beam bulb holder with ignition on and engine off. 9.5 volts. Bulb illuminated when main beam switch on.

It does seem odd that the contacts in the bulb holder are registering 9.5 volts without the bulb lighting up.

I've not yet traced the wiring to check for visible faults (I will when the tank isn't full of fuel). Before I do, I would like to ask the forum if this could just be a faulty pressure sensor?

Thoughts?

Regards

RobC

Oil pressure sensor, they only seem to last a 3-5 years. In fact on my 1150 the original only lasted 3 months.

 

[robc76]

Mine is at least 17 years old as I've never changed it in my ownership

RobC

 

[jacksdad63]

Update: I pulled the spade connector from the oil pressure switch and the wire fell away so corrosion had crept in. I fitted and new connector and cleaned up the terminal. With the connection made, the oil light remains off. When grounded to bike, the oil pressure light came on meaning the wiring is good and the switch is faulty. A new one will be ordered tomorrow.

Thanks for pointing me in the right direction chaps.

Regards

RobC

I needed an oil pressure switch for my R1100RT, I got one for a BMW car that was the same pressure rating, they are much the same on most engines, cost me £3.50

 

[robc76]

Good to know.

Does anyone have a comparable part number for a car?

Regards

RobC

 

[Neil W]

Think I changed the switch twice on my first 1150 and the one I have now has paperwork showing a switch purchased , I think there is a cheaper alternative which is a standard car one that is not subject to BMW Motorrad Tax

Double check but I was told this one is a direct replacement for post 1998 bikes

1277642 - Oil pressure switch OE number by BMW | Spareto

Replacement parts compatible with OE numbers 1277642 (bmw): HERTH+BUSS ELPARTS®70541039, VEMO®V20-73-0125

spareto.co.uk

 

[Neil W]

Supposed to be the same as the following BMW cars

Oil pressure switch ERA 330348 compatible with the following popular cars​

Car models	BMW E30; BMW E28; BMW E12
Engines	316 i; 316; 318 i; 518i; 518 i; 518
Engine power (horsepower)	90-105 hp
Power (kilowatts)	66-77 kW
Year of manufacture	1974-1991
Manufacturer article number	330348
OE part number(s)	61 31 1 243 414, 12 61 1 277 642, 61 31 1 354 272

 

[jacksdad63]

Good to know.

Does anyone have a comparable part number for a car?

Regards

RobC

I fitted a 'genuine part' Febi 04428 switch, trade price was £3.74. Fitted June 2023, no issues at all. Its just a standard, basic pressure switch, after all! Mine had the light staying on problem, but it then went off, pointed to being the switch right away. If you fit one, the light goes off, its fixed, thats it.

 

[jacksdad63]

Supposed to be the same as the following BMW cars

Oil pressure switch ERA 330348 compatible with the following popular cars​

​

Car models	BMW E30; BMW E28; BMW E12
Engines	316 i; 316; 318 i; 518i; 518 i; 518
Engine power (horsepower)	90-105 hp
Power (kilowatts)	66-77 kW
Year of manufacture	1974-1991
Manufacturer article number	330348
OE part number(s)	61 31 1 243 414, 12 61 1 277 642, 61 31 1 354 272

The thread is M12x1.5, 12mm long, switching pressure range 0.2 to 0.5 bar. I think it was listed for the 2.0 and over BMW motors, and the Mercedes Sprinter and Vito vans.

 

[The Other PaulG]

A switch for my Monster was going to be about £50 from Ducati. My local Fiat dealer had the same part for under a tenner.

 

[jacksdad63]

A switch for my Monster was going to be about £50 from Ducati. My local Fiat dealer had the same part for under a tenner.

They are just a switch! Same as any other engine, it just switches when the oil pressure hits it, match up the thread and the wire connector and I reckon any small engine switch would work.

 

[robc76]

I've ordered the Febi part from my local factor. £4.50.

Regards

RobC

 

[jacksdad63]

I've ordered the Febi part from my local factor. £4.50.

Regards

RobC

Let us know how you get on! Tip: there are 2 thread types on switches like these, one is a straight thread, usually the switch will have a washer on it, these tighten up 'snug' and use the washer to seal the hole. Some have a taper, generally these parts don't have a washer, you just fit and tighten up gently, as the tapered thread goes in, it seals...do not overdo it! I just tighten up a little more than finger tight then run the engine, if the thread leaks, you can easily tighten it a quarter turn more. Better than stripping them, which is a real possibility on aluminium engines/tiny threads

 

[robc76]

Update: New pressure switch fitted this morning. It was a direct screw in replacement and it came with the required washer. It seems to function as expected with the warning light illuminated with the ignition and extinguished when the engine is started. Ran the engine for 10 minutes and no leaks are apparent but I will keep an eye on it for a while.

Thanks for the help folks.

Regards

RobC