www.iFourWinns.com

I need some clarification on my issue and the steps I have taken so far. My original issue: my temp gauge (within 60 seconds of starting the engine) would creep up all the way to full hot. I originally thought I had a blockage on the water inlet, but (like any brilliant mechanic), I tapped on the gauge and it seemed to fix the issue. The issue got worse the second time I took the boat out and tapping failed to correct the gauge. I am not very good at engine work, but I can feel my way through electrical troubleshooting, so I put an ohm meter on the disconnected sender wire (disconnected at both ends) and put one leg of the meter to ground (negative post on the battery) and I read ZERO resistance. I then traced the temp sender wire (post #3 on the Faria Combo gauge) all the way back to a wiring harness on the rear of the engine (just under a fuse / relay box) and disconnected that harness and the wire now shows 100% resistance. From the harness to the clip that attaches to the sender, I read ZERO (the wire has a dead short somewhere between the rear of the engine and the clip on the temp sender). If I meter the sender itself as it sits in a completely cool engine, I read 100% resistance (open circuit) which doesn't seem right to me. I know the resistance value changes as the water temp goes up, but should it start at full resistance?

Finally, when the sender wire is disconnected from the gauge, the gauge reads about 140 degrees. If I short Post 3 to ground, it jumps to full and if I remove 12V power, it falls to rest, but just with 12 volts and no sender wire shouldn't still sit at the bottom?

To me, it sounds like my temp sender wire shorted out back at the engine (slightly perhaps) causing the gauge to read a false HOT engine. Now I think as a result, my gauge is now faulty and my sender could have gone bad...does this sound possible?

I am thinking about adding a secondary (stand-alone) temp gauge to the dashboard and in doing so, do I need any special sender? Are temp senders standard (as far as temp-to-resistance ratio) and are gauges standard?

It's a boat, so - yes. Anything is possible. You shouldn't need to install a 2nd temp gauge. If yours is faulty, Faria will fix it. As to resistance of the sender - I'm not sure if cold=high or cold=low, but that information should be available. It might be just as easy to replace it though.

_________________


Mike
2005 Four Winns 230/240
VP 5.7GXi/DP
1998 F-150 XLT
Boat Pic

I contacted Faria about their RMA process and it could take up to 4 weeks AND if the problem is unrepairable, they will just sell you a new gauge (at a new cost + shipping). I did find my exact combo gauge on ebay
http://www.ebay.com/itm/Faria-Marine-Gauge-Combination-4-Inch-4-in-1-Chesapeake-White-Stainless-GF0008-/370819737139?pt=Boat_Parts_Accessories_Gear&hash=item5656942633&vxp=mtr
and based on the price of aftermarket temp only gauges, I would be best to just replace the exact unit. If I can find the part number for my sender, I may just replace the whole shebang!

Its been a pain to find any information on the temp sender as far as specs. When I called Faria, they said that the temp reading should be 1.2k ohms at 60 Degrees and something like 800ohms at 170 Degrees (something like that). But in the end, nothing really shows the spec's on these. I wouldn't mind cruising down to my local NAPA auto parts store and grabbing the sender and being done with that chapter.

I have a big 4th of July trip coming up in Coeur d'Alene, ID and have to have this resolved by then. Gotta make good use of that boat in the summer

I had my all-in-one taken care of by Faria earlier this season for the same issue. It took two tries, as when they sent the one back, the volts didn't work. They promptly sent another and haven't had any issues. For resistance values, check Faria's website. I found a doc that has values for ALL sending units. Here are the values you need...

100F=450 ohms
175F=99 ohms
250F=29.6 ohms

hope that helps.

As I did at the time, try taking your sender and gage out. Wire everything together and put the sender in water on the stove.... see where I'm going? Should take all the "boat stuff" out of the equation, and determine if the sender or gage is a problem before you get into the wiring.

_________________
Walt B
"Debt-Charged"
Black '07 H210SS
6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.

What a mess. So I purchased two sensors for this project - 872068 and 3852029. I Really, honestly cannot figure out what the heck is going on. I am pretty sure I need a new gauge (which showed up today), but these sensors make no sense to me. Originally I thought I had found a bad temperature sender, but after a few days of thought, I realized that is physical location on the engine (on the thermostat housing) really wouldn't read an accurate engine temp because no water flows until the thermostat opens. So this would read the temp of the "water, ready to cool" so to speak. Here are some links with narrations explaining what I found and now my biggest concern is "what in the hell does sensor "A" do and why is the wire connected to it a ground? What is the point? Any suggestions are greatly appreciated!!!

http://i659.photobucket.com/albums/uu31 ... 01ea8a.jpg
http://i659.photobucket.com/albums/uu31 ... 811d50.jpg
http://i659.photobucket.com/albums/uu31 ... f34771.jpg
http://i659.photobucket.com/albums/uu31 ... 82857f.jpg

Isn't sensor A an overheat detector, connected to the ECU to make it go into limp mode and possibly sound an alarm ? On the later engines there are also overheat sensors in the risers.

If you use the "Img" button, then your pictures will display inside your post.
Each picture post should look like this: {Img}http://i659.photobucket.com/albums/uu315/aaronwgraff/Boat%20Issues/1_zps7a01ea8a.jpg{/Img}
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_________________

"Knot Easy" 2000 Horizon 240 Volvo 5.7GS /SX
tow: 2017 Honda PILOT EXL-AWD
prev. boats:
'87 Chaparral 198CXL 4.3 OMC Cobra
'69 Jetstar 16ft Ski Boat, 115hp Yamaha
'68 Aluminum Jon Boat, 3hp Sears
'64 Water Wings

Grahm - It totally makes sense that Sensor A is an overheat detector (as it is either an open circuit or closed circuit). Why would the wire connecting it be grounded? That's what I am having a hard time with. Is it possible that the overheat detector system is an upgraded "bell or whistle" and my boat is not equipped? I also have two sensors on the exhaust manifolds but nothing to monitor their status (gauges, alarms, etc).

Are there not 2 connectors on it ? If only one and it's connected to ground ( the engine block/ battery negative) then whether it's open or closed, it does nothing.

I know, right? The only way to know for sure is to completely unwind the taped wire harness.

Perplexing, but I think I have an explanation !

I'm not certain what year your engine is, but it must be 2006 or 2007. I looked at the wiring diagram I have in a VP manual. Specifically the wiring diagram for the 4.3GL-F/ G and 5.0GL-F/ H ( F is 2004, G is 2005 etc).

Assuming the wiring is similar or the same as on your engine; the oil pressure gauge sender and the water temperature gauge sender are shown. Also:

1. It shows the starboard exhaust riser overheat switch.
2. It shows the port exhaust riser overheat switch.
3. It shows an oil pressure switch
4. It shows your "switch A"

All four have tan/ black stripe wires and they are all linked together within the harness, terminating in pin 4 of the engine 14 pin engine connection multiplug.

So, if any of those 4 switches have failed in the closed ( i.e. to ground) activate alarm position, then the others will also be connected to ground via that switch! You need to look elsewhere for the switch that has actually failed.

I hope this helps you.

Graham

I was wondering where switch A was on my 5.7GXi, I didn't recall ever seeing such a switch. For information if it comes up again, , the EFI models do not have it! The temperature gauge sender is different, with more cables. It, the oil pressure sender and 2 riser switches feed into the ECU, the ECU connects to pin 4 with a tan/ black wire.

So, the GL engines have the alarm, but it doesn't trigger a limp home mode.

The EFI have the limp home mode plus the alarm.