I have a M35A Universal/Westerbeke and my oil sensor switch has failed.
I can't seem to find the part number or even a parts list for the M35A. The "Tech Notes" only has a parts list of the M25 and the M35B. Is it the same part number as the "B" does anyone know? And anyone know of a good source? Appreciate any help.
Thanks
Sam:o
—
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
Sam, this page is part of the parts listing at Marine Diesel Direct, there's a link at the top to the entire catalog for the M35A:
[URL="http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&p..."]http://www.marinedieseldirect.com/catalogs/catalog_group.php?owner=mdd&p...
shows the last item as being the oil pressure sender. However the price is an eye watering $177. I bought one of these when we got our boat as it had been butchered with a single line switch which killed all the alarms and I wanted it back to OEM. I got it from the Universal dealer up here and I know I did not pay that for it but I'll have to search through some invoices and see what I got. Problem is we are at the boat until the 29th of July. If no one else comes up with anything before then I'll check and see what I can find when I get home. It's probably available at NAPA, I'd just take it in and see if they can match it. It'll be maybe 5 bucks there.
Thanks for your help Bud. But I looked at the picture in the link and its definitely not the same as the one on my M35a. Actually mine looks like the drawing of the one on the M35b in the tech notes. I found a source for that one at $15 bucks. I'll try calling that source tomorrow and ask if they know if it fits the M35a. Thanks for the help.
Sam
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
That picture is probably just supposed to be representative, it's not at all what mine looks like either in fact there's nothing on my engine that looks like that at all! Pretty sure I paid about 15 bucks for it. Good to hear you found one, it probably will be fine they're kind of a stock item at a lot of auto parts stores.
Dumb question department... What is the method to use to test one's oil pressure sender?
Joe & Patti Worth
"Tehani"
1999 C36 MKII #1810
Atlantic Highlands, NJ
Slightly off topic - same question on how to test the engine temperature alarm sender?
Joe & Patti Worth
"Tehani"
1999 C36 MKII #1810
Atlantic Highlands, NJ
Sam , I purchased a Westerbeke 37323 O/P switch thru Marine Parts Source Marysville , MI. (1465 Michigan Ave) for $15.80. Their PN is JHw-37323. hope this helps.
BTW , my 1994 has a M35A diesel.
Larry, Yes, that helps. in fact that should solve my problem. Thank you very much.
Joe, that's not a dumb question but I believe the way to check the oil sensor switch on my M35A is to use an ohm meter, pull off the wires, then check the resistance across the terminals. I believe this switch is "normally closed", that is when the engine is not running, the switch is closed. When the key switch is turned on that allows current to run through the oil pressure switch, completing the circuit with the warning siren and the light on the panel, and they come on. That's why with the key turned on but the engine not yet started, you get the alarm. As soon as the engine starts, the switch detects oil pressure which opens the switch, shutting off the alarm until the pressure stops, ether through an oil pump failure, low oil, or the engine is shut down. So, if your ohm meter shows no resistance (completed circuit) across the switch with the engine off, then its good. If it shows a bunch of resistance, then the oil switch is open in the engine off mode and has failed. That is the case with mine and that's how I confirmed the switch was the issue. I hope I'm right.
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
Thanks Capt. Sam!
Joe & Patti Worth
"Tehani"
1999 C36 MKII #1810
Atlantic Highlands, NJ
I think it is the other way around. It is open with no oil pressure. The fuel pump is powered through the oil pressure switch. When you turn the key on there is no power to the fuel pump because there is no oil pressure and the switch is open. But when you put the key in preheat there is a solenoid that sends power to the fuel pump and it runs so you can start the engine. Once the engine starts, the oil pressure switch closes and completes another circuit that powers the fuel pump after the key is released from preheat. If your wiring hasn't been butchered there should be a light blue wire on the OP switch that goes to the fuel pump and another one from the preheat solenoid to the fuel pump.
The alarms work in a different way, when there's power on the light blue lines either from the OP switch or the preheat solenoid it shuts off. When that power is interrupted the alarm sounds. The water temp works the same way.
The idea is that if the engine loses oil pressure the OP switch opens, shuts off the fuel pump and saves the engine. Might be a good idea except for the fact that the Mk II will siphon feed and keep running without a fuel pump.
This whole area is overly complex, probably needlessly. Right Stu? But I wanted it to match the wiring diagrams so I put it back to OEM, the PO had put in a single terminal OP switch and ran a line from the ignition to the fuel pump and that killed all the alarms.
I have the wiring diagrams and can post them if anyone's interested.
Ok but I'm pretty sure my boat is not wired the way you describe. First of all my fuel pump comes on when the switch is turned on, before its pushed to the glow-plug preheat mode. Think about it. If it were otherwise, then you would always need to excite the glow plugs to run the fuel pump. I never rotate the switch to the preheat when the engine is already warm. Also, on my boat at least that preheat mode is spring loaded and as soon as its released, the preheat is off.
Also, I can make my oil pressure alarm, siren and light come on by Jumping the leads to the switch, just as it should be if the switch were operating correctly, before engine start.
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
Sam, the way I described it is the way the M35A is wired, I think the B is wired that way as well. There have been numerous discussions about it on this forum and the C34 forum. Your boat may have been altered or wired differently from the factory. Did you get a manual with your boat? There should be an engine manual in there with a wiring diagram.
I will post the wiring diagrams later today when I get some WiFi. You don't need to run the fuel pump for warm starts, only cold so it actually works seamlessly but it is overly complex and since it doesn't protect the engine on a Mk II from loss of oil pressure as it was intended to do, it's pointless.
I posted the Westerbeke/Universal wiring diagram in the Owner's Encyclopedia this is the link:
[url]http://www.c36ia.com/node/2277[/url]
This diagram is from 1991 to 2006 and includes all engine models. It matches what is in my owner's manual for my M35A, and my fuel pump/alarm/glowplug/OP switch wiring now matches it.
If your boat has a single contact OP switch then something is not right, as far as I know they were all built with double contact OP switches.
Note also on here they show the oil pressure sender, that was only for panels that oil pressure gauges and I don't believe any Catalina ones ever did.
The panels shown are Westerbeke and since Catalina had panels built by Seaward they are not perfect but the panel wiring is very close with only a few minor differences. When I converted my panel from the old style to the new style it was virtually identical.
Your boat could be different, I've never seen it, but for both Catalinas we have owned this diagram matched and from the discussion over the years about this issue it is my understanding they all were wired like this at the factory. But all boats are unique so who knows?
I wanted my wiring to match the OEM wiring, it is easier to trouble shoot if you know what you have and it matches the factory diagrams. Any additions I made, such as the regulator, alternator, charging wiring, engine panel, I did Visio wiring diagrams for both the original and changes.
Bud, thanks for the details and schematics. I'm no electrician, but I'm studying them. My owners manual is on the boat. I'll check it when I go down later this week. But from what I know now, my boat is not wired that way. when I turn on the key, before pushing it to spring loaded heat-the-glow-plugs stage, the oil pressure alarm comes on (used to before switch failure) and the fuel pump runs. All before the engine in cranked. My oil sensor switch is two pronged. And when I pull off the two wires from it and touch them together or put a jumper wire between them, then turn on the key, I get the alarm light and siren. The fuel pump runs when the key is turned on even when both wires are de-attached from the OP switch.
So, now I'm worried that my system has been messed with wrongly?
I've ordered the OP switch referenced above. When I get it, I'll check it with my ohm meter, if its closed I'm thinking its the wrong switch for me???
Maybe I'm confused.:confused:
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
Here is the wiring diagram and a photo of the switch. I have an Oil pressure switch rather than sender. The switch in normally open ( when engine is not running) and when pressure develops it closes and places a short across the soanalert terminals - then the soanalert makes no sound. The pressure switch must have the right pressure rating - the one from the auto store may not have the correct pressure rating. Oil Pressure part number Universal Part Number is 037323 about $ 24.00 from Transpacific -Distributors - located in Fairfield.
Transpacific Distributor
941 Waters Court
Fairfield, CA. 94533
707 426-6670
707 426-0206 fax
[url]www.marinegate.com[/url]
[email]info@marinegate.com[/email]
Haro Bayandorian, 1999 C36 MKII, Sail La Vie #1787, M35B,
Coyote Point, San Mateo, CA.
Sam, my start up sequence is this:
Turn ignition key on - alarm sounds, fuel pump does not run (OP switch open)
Turn key and hold at pre-heat - alarm shuts off, fuel pump runs (power being supplied from the glow plug solenoid runs fuel pump and shuts off alarm)
Push starter, engine starts, release key - alarm off, fuel pump running (power being supplied now through OP switch)
If I do this at step 3 - Release key, push starter, engine starts - the alarm comes on and then shuts off when the engine starts. That's because for the interval until the OP switch closes there is no power to the fuel pump and the alarm.
It's pretty common for owners to have changed this wiring because it is hard to understand, as I mentioned our boat had been changed so that it operates like yours. Trouble was it was done in a very mickey mouse fashion and was a nightmare to troubleshoot which is why I put it back to OEM.
Haro's diagram simplifies it a lot more than the wiring diagram.
Your help very much appreciated. Who knew this could be so darn complex. Oh, I forgot, its a sailboat! I'm having a hell of a problem just acquiring the darn OP switch, company I placed the order with on Saturday called today to tell me they couldn't sell to Florida. Called the Dist. in Florida and they're only wholesale without a dealer in my town. Called a dealer 2 hours away and he has to charge me two shipping charges, one from wholesaler (same one I called) and another to me. Whooosh! what a fandango! Local auto parts house, says they can probably find it if I bring in my old one. I think that's what I'll try next. Gotta love a challenge.:D
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
OK, the switch I ordered arrived and I installed it today (p/n 037323) its a normally open, two pronged switch and looks exactly like the one I took out.
Only now I'm convenced that mine was a normally closed two prong that has failed. With the new one installed, I turn on the key, no sound, no warning light, fuel pump runs. Then engine starts and alarm siren and light come on. So, right, the switch I got and the one most of you have is a normally open switch which closes when the oil pressure comes on. Mine was not. I see now, a cut wire at the contact to the switch, so a previous owner definitely had the system rewired. So now I must try to go find a normally closed two prong switch like the one I had that failed or try to rewire. Damn, why is all this so hard? I just want to go sailing.:confused:
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
FWIW, my advice is to take the time to put it back the way it was at the factory. It will make your life far easier in future when you are chasing problems. You will have an accurate wiring diagram and any competent mechanic, which admittedly is a rare find these days, can use it to trouble shoot. But if it's been hacked and is undocumented you are always going to have a hard time figuring stuff out.
That was my rationale on putting it back the way it was from the factory and it has paid off. It wasn't really that difficult to do either, just had to open some wiring looms and find where they had cut into and through wiring and fix it. There were two they just whacked in half and left dangling in there. Live 12V feeds. Nicely done!
Since I can't find a switch that is normally closed, I probably have no choice but to take your advice. I admit that I'm intimidated by it but I'll have to dive in. The problem is that I can't just re-wire it the way the original schematics show because the PO installed a newer eng, inst. panel that has different gauges, Tach, WT, voltmeter, and fuel. No OP gauge. But I'm sure given time, lots of time, I can figure it out. Pray for me. Thanks for the help.
Sam
:eek:
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
Ok, here's the rest of this story for anyone still interested. I finally got a good guy at my local (Pensacoloa) Westerbeke dealer to go to them and do the search. He found that yes, there is an OP switch that is two pronged and fits, that is normally closed, opens under pressure and is what I had that failed. for anyone interested, its p/n 011552. It was in stock. I got it and installed it and all is well aboard Wind Rose. It was almost twice the price as the one most of you apparently have (p/n 037323, normally open, closes under pressure) They look identical except mine is copper colored and the one that didn't work is silver. but I just didn't have the time right now to tear open all the cables to figure out how my system was altered and rewire to accommodate that switch. I'm hoping these little buggers don't fail but once in a life time and I won't have to pay for this later. But in the meantime, I'm going sailing and if anyone wants the brand new 037323 that I have I'll be happy to send it for free. Just give me the shipping address. Bud? it the least I can do for all the help.
Sam
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
So glad the mystery is over and you are sailing again, Sam.
Thanks for letting us know...'the rest of the story.'
Duane Ising - Past Commodore (2011-2012)
s/v Diva Di
1999 Catalina 36 Hull #1777
Std rig; wing keel, M35B, Delta (45#)
Punta Gorda, FL
http://www.sailblogs.com/member/diva-di/