www.iFourWinns.com

After changing belts (another thread) I spent some time wiping bits of old rubber of my engine. When I took the boat out for a test run, the temp gauge was flatlined (all the way down)(off the gauge) - never moved. Clearly I inadvertently disconnected the sending unit? Anyone able to tell me where it might be? I don't want to spend my upcoming trips through the San Juans with nothing giving me engine temp.

Thanks, everyone here is a life-saver.

Mark
1996 FOUR WINNS SUNDOWNER 205
5.0L (fuel inj)

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

Red arrow is your sending unit.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

Niagra, thanks for the reply. I don't understand a bit of that diagram, I'm sorry. ANy chance you could point me in the right direction from this photo?
The thermostat on the dash is just dead. Thanks!

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

I can't view your pic on this computer (dang work filters ), but as you look at your engine from the front, that sending unit should be to your left, in the front area of the intake manifold.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X

^^^ Correct.
Almost underneath the starboard side of your thermostat housing (tricky to see!).
It will be a brass plug, with an electrical terminal on top...

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2011 Four Winns H180 SS.
Aussie built Mustang 2800.
SOLD - 1997 Four Winns Horizon RS

see the wire under the thermostat ? follow that wire should be it

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1989 245 vista
5.7 cobra

This wire? Looks like it's plugged into the block. I removed the nut (it was loose) and lost the washer. I used a common washer and put it all back on and somehow stripped the thread on the nut. Now it won't tighten or loosen. AND, now the engine won't start. Am I screwing this thing up royally? Engine just clicks, really fast then slows down to nothing. Dead battery is almost impossible...could I have shorted out something?

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

Not sure what that is (never had a Ford marine engine) but based on the schematic that Niagara posted, the temp sensor should be underneath one of the hoses coming off your thermo housing. Cold reading on marine inboards in my experience about 90% of the time is a sticky thermostat that does not close all the way. It could be a gauge, sender or wiring problem, but I've replaced at least 5-7 'stats over the years for this same problem. A piece of rust gets in the seat. So what I learned:
run the boat up on plane, let the engine get at least to 160 where the stat starts to open. Then take a large wrench and tap on the thermo housing, this can dislodge a piece of rust stuck there and lets the stat close. Then it will run at normal temp. If this does not work, you have to change the stat.

Your engine is EFI, this should be what you got:


http://www.crowleymarine.com/johnson-ev ... /56697.cfm
this # 25 is the water temp switch

here you go the thing you fiddled with is in the water pump actually....it is also a sending unit...probably for the EFI system..

http://www.crowleymarine.com/johnson-ev ... /56696.cfm

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Thanks for taking a look. Here's a closer shot of it -- is it indeed the sensor? It's screwed into the block (I see threads). And it has a tan wire leading to/from it.

I appreciate the feedback. Trying to learn. But I may be screwing this up and making it worse. 1 week to go to our long trip into Puget Sound -- I figured I wouldn't want to do it without a temp gauge working properly.

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)

Yep, that's the guy. I took a tester to it and when I touched it the gauge popped up and down. Very easy to find, not hidden at all on the Ford version of a Four Winns 205 Sundowner.

So on another thread I told you about how, after cleaning what I thought was the thermostat connection, the engine bonked. Just went dead. Turns out it was a starter connection. I had THREE connections go bad within one week:

Belts got loose (that started my adventure) because alternator got loose.
Thermostat wire was loose.
Starter connection loose.

Once I got the starter figured it, it all came together - including that gauge. The thermostat popped right on and works. Sometimes, however, those Volvo Penta/Ford machines are so efficient it's hard to tell if the engine even heats up. it rarely ever got to 140 degrees over the years. Usually sits around 125-130 (sea water and cold river water are our two main running sites)

I am composing a polite note to the mechanics who worked on my boat the last three years. So disappointed the shop would do such shoddy work (not even putting a nut on the alternator bolt, etc) I pay these guys every year a lot of money IMHO to winterize and make sure all connections are secure. These would appear to be basic maintenance procedures that I pay someone to look after.

I've learned a lot in this process. I will always follow up and check these things myself out before I go out on long trips - even if I pay someone to (supposedly) look after them.

Thanks, everyone.

Mark

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Four Winns 1996 Sundowner 205
5.0fi/SX engine (Volvo Penta)