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Obsolete temperature switch, what are the options?

N

Northern River

Member
1995 johnson 90 H.P., defective port temperature switch, original part number 514388, seems it was changed for 0585023. This part is no longer available, obsolete according to BRP. Besides a used part sold at a big price without knowing if it's any better than the old one, or how long it will last? What are my options? Thanks a lot for your help.
 
As a last call, so to speak... you could always stick a starboard sensor in there and do away with the fast start feature. After all, who needs that feature anyway?

It saves one from simply advancing the throttle slightly off idle.

If one doesn't know how to start the engine, they shouldn't have it in the first place.
 
You are aware that the same SWITCH with a different plug in connecter would have a different part #----So check with your friendly local authorized shop and not AMAZON.
 
racerone said:
How did you determine / prove that your switch is bad ?
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I followed the testing procedure in the OMC Shop manual, gave it a hot oil bath and at 260 degrees F the switch did not close the circuit, the fast start circuit did close at around 105 degrees F. The starboard switch did close the circuit at around 240 degrees F. I ran the test because the overheat alarm has been going off once in a while since the last 3 years. But I never saw signs of overheating, no steaming, no lack of power steady RPM at full throttle, it runs great. Tested the thermostats, replaced the water pump and flushed it just the same. I was expecting to find a switch that was closing at operating temperature, it was not the case. Could it be possible that the defective switch closes the circuit intermittently at operating temperature? I will also check the wires for shorting to ground intermittently.
 
joereeves said:
As a last call, so to speak... you could always stick a starboard sensor in there and do away with the fast start feature. After all, who needs that feature anyway?

It saves one from simply advancing the throttle slightly off idle.

If one doesn't know how to start the engine, they shouldn't have it in the first place.
Click to expand...

Thanks Joe for educating me, this is certainly a good option. I will look up the fast start feature just for my knowledge. You have been helpful in the past and you are helping me again, faster than the dealers that I have asked for advice.
 
racerone said:
You are aware that the same SWITCH with a different plug in connecter would have a different part #----So check with your friendly local authorized shop and not AMAZON.
Click to expand...

Thanks Racerone, this is a good option too, the shops visited, never suggested a substitute switch other than looking for a used one. Some didn't even bother returning my call. They probably figure that a 24 years old engine is ready for retirement and sell me a new boat altogether! Do you know if there's some kind of compatibility chart for these switches?
 
Northern River said:
Thanks Joe for educating me, this is certainly a good option. I will look up the fast start feature just for my knowledge. You have been helpful in the past and you are helping me again, faster than the dealers that I have asked for advice.
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Joe if I opt to install a starboard switch as a replacement for the port, do I need to do anything else besides changing the electrical connectors and grounding the white and black wire that goes to the power pack? Thanks again for your help.
 
If grounding the black/white lead that goes to the powerpack disengages the "Fast Start" feature... that's it.
 
joereeves said:
If grounding the black/white lead that goes to the powerpack disengages the "Fast Start" feature... that's it.
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Joe I just came back from a BRP (OMC) dealer to either buy a starboard switch to replace the port switch (2 wires) and ground the wire going to the power pack (fast start), or to try and find a substitute (as recommended by Racerone) that would fit my 1995 90 HP Johnson and replace the electrical connectors (in both cases) and I was told by a technician that the double wired port side switch had a diode built in and that I was looking for trouble if I grounded the wire going to the power pack or if I replaced the connectors. So I came back empty handed and puzzled. And forget about a substitute they will not give me one. I do not doubt your competence just need to be reassured, thanks, Frank
 
Northern River said:
Joe I just came back from a BRP (OMC) dealer to either buy a starboard switch to replace the port switch (2 wires) and ground the wire going to the power pack (fast start), or to try and find a substitute (as recommended by Racerone) that would fit my 1995 90 HP Johnson and replace the electrical connectors (in both cases) and I was told by a technician that the double wired port side switch had a diode built in and that I was looking for trouble if I grounded the wire going to the power pack or if I replaced the connectors. So I came back empty handed and puzzled. And forget about a substitute they will not give me one. I do not doubt your competence just need to be reassured, thanks, Frank
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Well, without giving it a lot of thought and just running the circuitry through my head a couple times... this is the first I've heard about a diode but if it exists, it would be to prevent a interference between the two heat actuated contacts within one unit I'm thinking... BUT... changing to a single wire heat sensor eliminates that conflict and reverts the system to a proven circuit (overheat only) that has existed for years.

Personally I don't know for sure if that Black/White wire eliminates the "Fast Start" feature simply by grounding it out or not... BUT... if it does, and the grounding out is performed by that switch within that is coupled with the port overheat sensor... then the grounded circuit is the same all the time the engine is running whether it's grounded directly from the powerpack black/white wire to ground or via that expensive, over-priced non available two wire barrel.

If my two above paragraphs hold true... I can only wonder what solution to your problem was going thru that technicians mind.
*******************
If my above thoughts are in error, I'd appreciate having other members with the advanced knowledge to jump in here to set me straight as I'm in a sort of borderline knowledge area here due to retiring in 1991... and a ohm test I did on a few of those two wire barrel units as follows:

Having two or three of the 2 wire (Fast Start/Overheat) sensors (new) a number of years back on my bench, I seem to remember..... When checking it out that the Tan wire with a ohm meter, the heat sensor circuit was "open" normally, "closing" only if overheated (No problem)... BUT........

When checking the Black/White wire with a ohm meter, that Fast Start circuit was closed (cold). <-- That sticks in my mind. I didn't reverse the meter leads as I wasn't aware of a possible diode being in that circuit, never gave it a thought. I sold out of them so there's no way I can redo the test. Those overpriced things never came back so they must have been okay.

Unfortunately I can't remember if both units engaged via a certain temperature by grounding out... or one grounded out, and the other becoming open.
 
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joereeves said:
Well, without giving it a lot of thought and just running the circuitry through my head a couple times... this is the first I've heard about a diode but if it exists, it would be to prevent a interference between the two heat actuated contacts within one unit I'm thinking... BUT... changing to a single wire heat sensor eliminates that conflict and reverts the system to a proven circuit (overheat only) that has existed for years.

Personally I don't know for sure if that Black/White wire eliminates the "Fast Start" feature simply by grounding it out or not... BUT... if it does, and the grounding out is performed by that switch within that is coupled with the port overheat sensor... then the grounded circuit is the same all the time the engine is running whether it's grounded directly from the powerpack black/white wire to ground or via that expensive, over-priced non available two wire barrel.

If my two above paragraphs hold true... I can only wonder what solution to your problem was going thru that technicians mind.
*******************
If my above thoughts are in error, I'd appreciate having other members with the advanced knowledge to jump in here to set me straight as I'm in a sort of borderline knowledge area here due to retiring in 1991... and a ohm test I did on a few of those two wire barrel units as follows:

Having two or three of the 2 wire (Fast Start/Overheat) sensors (new) a number of years back on my bench, I seem to remember..... When checking it out that the Tan wire with a ohm meter, the heat sensor circuit was "open" normally, "closing" only if overheated (No problem)... BUT........

When checking the Black/White wire with a ohm meter, that Fast Start circuit was closed (cold). <-- That sticks in my mind. I didn't reverse the meter leads as I wasn't aware of a possible diode being in that circuit, never gave it a thought. I sold out of them so there's no way I can redo the test. Those overpriced things never came back so they must have been okay.

Unfortunately I can't remember if both units engaged via a certain temperature by grounding out... or one grounded out, and the other becoming open.
Click to expand...

That white and black wire is an open circuit until it reaches approximately 105 degrees F. according to the shop manual, and it's exactly what was measured with the ohmmeter in the hot oil bath, then it's grounded, the question is why is there a diode, it's job is to let either neg. or pos. current to go through, if I have to do the test again and inverse the polarity of the ohmmeter to verify the existence of a diode I will and keep you posted. Thanks again
 
racerone said:
Make an offer for a good used switch .
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With all due respect, I was thought to never replace an old part by another one, when you buy a new electonic component you can't return it, no way I would buy a used electronic component, especially when they look older than my used one, and as expensive as a new, I'll be patient as a fisherman! Let's keep working on a durable solution. Thanks, Frank
 
Northern River said:
That white and black wire is an open circuit until it reaches approximately 105 degrees F. according to the shop manual, and it's exactly what was measured with the ohmmeter in the hot oil bath, then it's grounded, the question is why is there a diode, it's job is to let either neg. or pos. current to go through, if I have to do the test again and inverse the polarity of the ohmmeter to verify the existence of a diode I will and keep you posted. Thanks again
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I appreciate the speedy reply my friend. Yeah... that diode mention puzzles me. Having both components engage due to grounding... what purpose would it have. Perhaps that mentioned "technician" in post #10 has it confused with something else.
 
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What's the model number of that engine?<-- Cancel this, not needed. regardless of model#, the starboard heat sensor part# comes up the same. On this site, 5850442 --->585184 at $81.75.

If it was me, I'd do away with the Fast Start feature in the manner we discussed earlier (grounded) and revert to the overheat system of yesteryear. Since the powerpack is in grounding mode of that white/black lead when running... what harm does it do to keep it grounded permanently?

Frankly I suspect that diode mentioning tech had the sale of a new engine on his mind. Did the personnel at that dealership actually refuse to sell you what you wanted? If so, that's discrimination... against the law isn't it?
 
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joereeves said:
What's the model number of that engine?<-- Cancel this, not needed. regardless of model#, the starboard heat sensor part# comes up the same. On this site, 5850442 --->585184 at $81.75.

If it was me, I'd do away with the Fast Start feature in the manner we discussed earlier (grounded) and revert to the overheat system of yesteryear. Since the powerpack is in grounding mode of that white/black lead when running... what harm does it do to keep it grounded permanently?

Frankly I suspect that diode mentioning tech had the sale of a new engine on his mind. Did the personnel at that dealership actually refuse to sell you what you wanted? If so, that's discrimination... against the law isn't it?
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I agree with you, since I have been inquiring about these switches I didn't get as much attention as the guy buying a 60K$ boat. The part person was worried about screwing up my engine. I needed to think about this a little more so I left but I told him that I might be back for the starboard part. They had no solution for me. Thanks a lot for your time Joe, once I've got this thing modified I'll let you know the result, it will take a few days but I'll get back to you. Frank
 
Just checked the fast start circuit on the switch, and current passes through both ways (polarity reversed) with the ohmmeter when the switch is closed (warm), digital ohmmeter set at 200K scale, no resistance at all, so direct to ground. I ordered the starboard switch an receptacle connector. Should receive around the end of the month. I'll keep you posted. Have a great weekend.
 
Northern River said:
Just checked the fast start circuit on the switch, and current passes through both ways (polarity reversed) with the ohmmeter when the switch is closed (warm), digital ohmmeter set at 200K scale, no resistance at all, so direct to ground. I ordered the starboard switch an receptacle connector. Should receive around the end of the month. I'll keep you posted. Have a great weekend.
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Well Joe it's done, single wired switch on the port side, grounded white and black wire, lift idle lever to start, starts and runs real good with the muffs. So thanks Joe because I would not buy another engine because of a stupid switch. If you weren't so far down south I'd buy you a pint of good Canadian beer. Take care, Frank
 
Thanks Racerone for your suggestions, did not get the help from the BRP dealer, so went with Joe's solution. You have helped me in the past and it's appreciated, if you were close to me I'd buy you a good Canadian beer! Take care, Frank
 
Northern River said:
Thanks Racerone for your suggestions, did not get the help from the BRP dealer, so went with Joe's solution. You have helped me in the past and it's appreciated, if you were close to me I'd buy you a good Canadian beer! Take care, Frank
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Well Frank, ya really stuck yer foot in it this time. I'm halfway down thru Florida in the Tampa Bay area, but yer other helper.... 2 miles down the roar, take the left fork, 3rd house on the left... a real boozer I hear tell! :)
 
racerone said:
And what is your location ?----You might not be far away.
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The city of Gatineau (neighbour to the nation's capital Ottawa located in the province of Ontario, only separated by the Ottawa river, did you see the pictures of our prime minister when he was in visit to India? No comment) located in the province of Québec the only french speaking bastion left in North America, in Canada. I like Florida, especially your parks, Disney and Universal, oh wow what a thrill that my 90 HP can't give me. Now I have to say that the people I met there were great. We are a lot more like cousins than you think, look at the film The Patriot with Mel Gibson, it's a piece of history (if it is). The statue of Liberty Wow, well anyways maybe someday we will meet and have a brew, take care. Frank (François in french)
 
Well that's the kind of trouble I like to get into, and mind you, I do like to enjoy a good cold beer in good company and a good glass of red wine with a good walleye treat, If I go down to Florida before I choke, I might give you guys a notice to meet, who knows what the future has in store for us. Take care, François
 
Well tested on the river, now the overheat alarm works too well (ahaha), it sounds off a few minutes after starting cold and shuts off after a few minutes at cruising speed. I'm under the impression that the new port side switch picks up the overheating faster, and that before the starboard switch picked up the overheating later. Could I have a bad thermostat that takes too long to open? Alarm does not kick in while running with the muffs. Thanks for your input guys.
 
joereeves said:
A faulty thermostat is always a possibility as is swelled water deflectors.
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Joe according to Seloc manual and the parts diagram on this site the J90ELEOC is not equipped with water deflectors, that's a good thing. I'll take the thermostats apart and probably just replace them, thanks, but if you think of anything else let me know, thanks again. Frank
 
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