Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

[SharpeCon]

My Temp gauge is not working, Can someone tell me what I can do to get it working? Also, After about 5 mins of the engine running a beeping alarm goes off in the console, I can turn it off by hitting the reset button. I dont believe the engine is over heating, Is there a place to add anitfreeze on this engine? Thanks for the help.

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

A/F is normally added to the heat exchanger if equipped with the fresh water cooling package(closed system), most are raw water cooled (open system)and use the lake or seawater for coolant.
On the thermostat housing you may see 2 brown wires going to 2 senders,
1 is a sender, 1 is a alarm.With the motor OFF,and key ON ground out the wire and see if gauge pins over.If it does ,wiring from sender to dash is ok and sender may need replacement.If it doesent move, a wiring issue.

 

[SharpeCon]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

I did jump the sender and the gauge did peg over. I just replaced the sender and the gauge is still not working??? Please help....

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

ok, the sender must be immersed in water to get a reading ,so assuming no water is present do the manifolds and risers feel hot.
For a quick test,(5-10 seconds) remove the inlet hose at the therm housing, using the muffs, start engine and see what/if any water comes out the hose.
Should be substantial

 

[SharpeCon]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

ok, water is in the hose full, so I assume water is coming out, the manifolds and risers feel warm after running it for 20 mins on the muffs but they dont feel hot. the new sender I got was not the same excatly as the old sender, the only diff was the metal stud thing that on the end that goes into the hole was shorter on the new sender... So maybe thats the prob? Bad ground somewhere? I dont have a voltmeter to test it either, I am trying to get on the water today, if I cant get my gauge working, is there a way to check or know if it is over heating? I did replace the impeller the other day. so I dont see a reason why it would overheat, This is my first boat, so I am a newbie

Thanks BT

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

when I suggested you ground the wire , where did you ground it.
did you use a jumper or just short the stud to the case.
did you just install the sender or use anything on the threads?
most therm housing gaskets have 4 brass grommets to ground the therm housing to the block itself. no continuity in the sender to the housing, the housing to the intake ,it may not allow the sender to work.The senders threads supply the ground.

 

[SharpeCon]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

what i did was take the tan wire off the sender and touched it to a bolt attached to the engine, it needle on the temp gauge moved all the way up to the other side. I did not put anything on the threads and i just hooked it back up the way it was before i took the old one off.....Im heading to the lake right now, I guess i will just check the engine often to see if its getting to hot? is that ok?

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

Hook it back on the sender and ground it using a jumper to the senders body.
just grounding the wire by itself checks the wiring to the gauge.grounding to the senders body verifies the grounding thru the therm housing to the engine.

 

[SharpeCon]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

So I took the boat out & here is what it did: The gauge worked, it didnt seem to over heat, but, at first it seemed to run fine except it would not go above 4000rpm's which is about 3/4 throttle. after it really got warmed up which is alot diff than having it hooked up to the muffs, and eventually it wouldnt even go over 2000 rpms... it just wanted to bog down when i throttled up. it probably needs a tune up and a rebuilt carb. Also the belts were squealing and one of them did burn up and break, but the boat did keeep running, so i'm not sure what that belt does? Any ideas or help would be great... Thanks!

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

http://www.boatfix.com/merc/Servmanl/18/18covr2.pdf
This might be useful

 

[SharpeCon]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

unfortunatly that manual stops at only what it plans to talk about ( the diff chapters)??? It also says it only covers mercruiser 4.3l alpha one's starting in 1993, mine is a 1989.... if you could post the correct link that would be great.... BT thanks again

 

[Bt Doctur]

Re: Mercruiser V6 4.3L alpha 1 Temperature Gauge Not Working?

Go to the adults section , there is a new way to download the files.
I`m getting #7 now but it`s 500meg