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
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.
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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.