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General Category => General Discussion => Topic started by: berniebee on August 09, 2022, 04:00:45 PM

Title: Oil pressure switch for older Guzzis- some info
Post by: berniebee on August 09, 2022, 04:00:45 PM
Soon after I got my SP1000 on the road, the oil pressure switch developed an intermittent condition where it would not activate the red indicator light when the ignition was turned on, but before starting the engine. Not a good thing, so the sticky switch had to go. From what I've read Moto Guzzi oil pressure switches fail and/or leak pretty often. 


(https://i.ibb.co/jvVTnDC/P1070707.jpg) (https://ibb.co/jvVTnDC)


There are plenty of switches that fit in the M12 x 1.5 threaded hole, but I couldn't find a substitute that had the Guzzi's long pin electrical connector.
It turns out that many BMW autos of the seventies and eighties use the same type switch, but with a common male spade connector. Common as roaches. And not expensive.

Next time you are in need, ask for a 1980 BMW320i oil pressure switch. There are several companies that make a compatible unit.  This one is from a company called Uro. (Get it? Euro. As in European car parts. )

(https://i.ibb.co/SyTYSFF/P1070708.jpg) (https://ibb.co/SyTYSFF)

It does have slightly a larger nut than the Guzzi part. (24 mm vs 22 mm)

Snip off the original pin connector from the harness, crimp on a female spade connector and you're done. I got fancy and reused the original rubber cover (boot) and some adhesive lined heat shrink.

(https://i.ibb.co/fQRcBgX/P1070714.jpg) (https://ibb.co/fQRcBgX)


(https://i.ibb.co/FHBLLfJ/P1070716.jpg) (https://ibb.co/FHBLLfJ)

And voila. If you should ever again need a replacement, it's a quick trip to your local car parts vendor.

(https://i.ibb.co/PxJycvy/P1070717.jpg) (https://ibb.co/PxJycvy)








Title: Re: Oil pressure switch for older Guzzis- some info
Post by: Antietam Classic Cycle on August 09, 2022, 04:09:49 PM
More information:
https://www.thisoldtractor.com/moto_guzzi_loopframe_oil_pressure_sending_unit.html

The 24 mm hex would be an issue on Loops with the original generator - the 21 mm original is already "too close for comfort" to the generator bracket.
Title: Re: Oil pressure switch for older Guzzis- some info
Post by: berniebee on August 09, 2022, 04:22:03 PM
Thanks Charlie. I probably should have titled this "for Tonti frames" rather than "older Guzzis".  :grin:
Title: Re: Oil pressure switch for older Guzzis- some info
Post by: Antietam Classic Cycle on August 09, 2022, 05:02:28 PM
Thanks Charlie. I probably should have titled this "for Tonti frames" rather than "older Guzzis".  :grin:

Nah, your title is fine. I was just providing additional information. 24 mm may clear the bracket on the Loop alternator kits.
Title: Re: Oil pressure switch for older Guzzis- some info
Post by: chuck peterson on August 10, 2022, 06:40:20 AM
Peugeot 505 used them too
Title: Re: Oil pressure switch for older Guzzis- some info
Post by: lucian on August 10, 2022, 07:35:29 AM
the oil pressure sensor on my Griso started leaking oil right up through the square electrical connector housing on top . I removed it and filled the connector housing with oil and introduced a little compressed air to the bottom of the sensor and you could watch it bubble right up through the oil. The replacement was right at Nappa for eight bucks.
 So for the later carc bikes with the square Molex type connector it's BMW part # 12617568480
Title: Re: Oil pressure switch for older Guzzis- some info
Post by: bigbikerrick on August 10, 2022, 10:58:00 AM
Good helpful information, guys. Its always nice to have alternatives.
Rick.