Low Oil Pressure Alarm

[Luana]

I have a concern about the low oil pressure alarm and/or oil sending unit on our (2004) Catalina 34 Mk II (hull # 1677)  .  The alarm stopped working in Aug.  It seemed to inadvertently go on/off then finally it stopped.  After inspection, I noticed oil on the oil sending unit and am thinking that this could be the issue and/or perhaps the wires need to be removed cleaned and re-installed before rushing out and purchasing the oil sending unit. 

The other issue might be the actual alarm which I believe is located in the pod that houses all the other gauges eg. fuel, water temp etc.  There is a large (round and serrated) nut that contains and holds the starting button in position.  It just doesn't want to move.  Because of its shape, I'm  limited by tools to remove it ie. large plyers, yet it simply doesn't move. Any hints on removing this nut? Of course the other issue might well be a poor connection. Any thoughts about this would be appreciated. The engine is a Universal M35B. Many thanks.

[Jim Hardesty]

Any hints on removing this nut?

Luana,
To remove the alarm buzzer take apart the engine instrument pod and hold one half of the buzzer and loosen the outer bezel (knurled nut) best tools are couple of channel locks.  Doesn't do any good to only loosen the bezel, the alarm would just fall into the pod or spin and break the connecting wires.  There is a recent and long thread pertaining to that alarm circuit. 
Myself I would clean the contact on at the sender.  If that didn't work then replace the alarm, it's cheep.  Here is where I got one.
https://www.greatlakesskipper.com/catalogsearch/result/?q=brp4535s-24-c&cat=
Hope that helped.
Jim

[KWKloeber]

You can follow the trials and tribulations of the elusive alarm here:
http://c34.org/bbs/index.php/topic,10000.0.html

My suggestion is to read everything from the beginning and try the same troubleshooting.

Mercy we need a Wiki site where this is all explained (once we are smart enough to sleuth it out) 🔎👁

-ken

[Luana]

Thanks for your suggestions. I did read some of the threads which lead me to start the trouble shooting from the wires connecting the sending unit. Of course, after loosing a pound of flesh, I hoped that there might be a less painful approach. Thanks again.

[Jim Hardesty]

Luana,
A suggestion.  Add your information to your signature, it's in profile.  See what others have done like. Boat name, Port, Year, Hull number, Model, Engine serial number and what ever you want to share every time you post.  It helps getting the best answers.
Jim

[Ron Hill]

Guys : A few years back I wrote a Mainsheet tech note article on improving the oil pressure switch longevity.  My fix - I carefully put some epoxy glue around the portion of the Bakelite to the metal (cleaned with lacquer thinner first).  I found a socket that would fit that goofy nut - I'm sure I mentioned the size in that article.  As I recall the thread is a tapered pipe thread and I cautioned about OVER Tightening. 

A few thoughts

[Luana]

Thanks Jim.  I returned to my boat today to re-visit the instrument pod.  I do understand what you are saying regarding the removal of the alarm.  I'm curious though, in order to remove the instrument pod, it appears that I have to remove the screws on the back of the pod. It also looks like I need to remove the nut on the ignition button so that I am not pulling on the ignition and wires.  It is this round retaining nut that is near impossible to remove.  I put some penetrating oil on it today and will attempt tomorrow.  The question is: do I need to take off the retaining nut that holds the ignition button.  Thanks.
Rod

[Luana]

Thanks Jim for the information regarding adding info to my profile.  I'm a relative newbie so I am still trying to navigate through the system.  I did go into my profile to add additional information however I am unable to do so.  Essentially I can add a 'call  name' and email address. Perhaps if I was an IA member I would be able to add more information.  I am seriously considering the IA membership.  Thanks and Cheers,
Rod

[Stu Jackson]

Rod,

Profile tab at top of these pages

Modify Profile in the left pane, choose Forum Profile, left click

Scroll down to signature, insert and finish by using Change Profile button lower right

========

The top box in Forum Profile lets you add an avatar photo and text

[Jim Hardesty]

it appears that I have to remove the screws on the back of the pod.

Rod,
Yes that's what and all you need to do.  Don't need to remove the start button.  Think the stearing wheel needs to be off also. Here is a tip for reinstalling screws into plastic.
Start the screws very lightly, you want to get the screws into the same thread that was previously cut into the plastic.  Helps sometimes to turn the screw backwards to feel the start of the thread.  If you are unfamiliar with reassembling screws into plastic, pratice a couple of times putting the screw in when the pods are split.
Hope that helps.
Jim

[KWKloeber]

Rod

The way the alarm circuit works on the B series, is the oil switch is normally (no oil pressure) OPEN.
The alarm is always powered with the key on and is grounded, so it sounds (or is supposed to.)
When there's oil pressure, the oil switch CLOSES, powers the fuel pump, and backfeeds voltage to the negative side of the alarm, thus canceling it. I don't know what voltage difference the alarm needs to sound off, but I suspect that backfeeding something like 5 bolts or less will cancel it. I really doubt it's a bad alarm but yahnevahknow.
Are the switch terminal tabs intact and secure?

K