running hot

[imraan47]

when boat is running...the riser (i believe thats what it is called -- see red arrow in pic)
is really darn hot.
my temp guage doesn`t work still.
replaced sender and therm

last time out i hooked wire from guage S`to `sender...and now the damn guage reads high constantly even when ignition is switched off.
actually to be more specific, when the ign is off the guage moves just a tad bit low but when ign on it goes back up to max!

waterpump, impeller and outdrive was serviced at the beginning of the season around June i guess.

 

[rickryder]

Re: running hot

Could you have a bad gauge? Have you tried disconnecting the sender wire at the gauge and does it read cold? Then hook a wire to the gauge and ground it? It should pin to hot when grounded.....

 

[imraan47]

Re: running hot

yup reads cold when sender wire at guage is disconnected.

 

[rickryder]

Re: running hot

If you put it to a ground will it pin on hot?

 

[imraan47]

Re: running hot

haven`t thought about doing that...i will have to try it and see. i am certain it will peak to hot.
its just sitting at hot right now constantly

 

[rickryder]

Re: running hot

Sounds like it's being fed a ground if it's pinned on hot.....Are you sure your on the temp sender and not hooked to an alarm sender?

 

[imraan47]

Re: running hot

boat doesnt even have an alarm system.
its really basic with guages.

http://i14.photobucket.com/albums/a304/imraan47/IMG_1004.jpg

it only started reading constant hot when i tried to bypass harness so what i did was took a wire and attached it to sender and the other end to S on guage. i kinda short circuited it alittle trying to attach it to S so i touched the other points and some sparks flew.
fuse is still ok though and i reset the circuit breaker.
actually i didnt think to remove the wire from sender that goes through harness first...i just linked it up on top of that.
i made that stupid mistake!

 

[rickryder]

Re: running hot

I would say your original wire is shorted to a ground somewhere...... just try it with your new wire Good luck

The alarm I'm talking about would be a low oil or overheat alarm..... most engines have one

 

[stackz]

Re: running hot

boat doesnt even have an alarm system.
its really basic with guages.

http://i14.photobucket.com/albums/a304/imraan47/IMG_1004.jpg

it only started reading constant hot when i tried to bypass harness so what i did was took a wire and attached it to sender and the other end to S on guage. i kinda short circuited it alittle trying to attach it to S so i touched the other points and some sparks flew.
fuse is still ok though and i reset the circuit breaker.
actually i didnt think to remove the wire from sender that goes through harness first...i just linked it up on top of that.
i made that stupid mistake!

this makes no sense to me. so you bypassed the harness by running a wire straight from the sensor output to the "S" terminal of the gauge itself?? and sparks flew out? thats not possible. all the sensor is, is a potentiometer which changes its ohm resistance based on how it reacts to increasing temperature from 0-320ohm with full cold being "0" and the max gauge reading as "320ohm".

when you say you shorted it, do you mean you had the bypass wire hooked up to the sensor and then accidently touched the wire to a positive terminal before setting it to the "S" terminal? if so, your brand new sensor is now fried, go get another one. thats why its reading maxed out and stays there.

any time you bypass a harness...make sure everything is isolated before you start wiring it up how you want.

 

[imraan47]

Re: running hot

when you say you shorted it, do you mean you had the bypass wire hooked up to the sensor and then accidently touched the wire to a positive terminal before setting it to the "S" terminal? if so, your brand new sensor is now fried, go get another one. thats why its reading maxed out and stays there.

yes thats what i meant to say. oh great...so now i need a new sender before it was even fixed.

 

[stackz]

Re: running hot

replace the sender, and dont hook it or the gauge "S" terminal back up to the original harness.

then run a fresh isolate wire from the gauge to the sender and you should get correct readings.

if you want to test it simpler. take the sender and the gauge inside the house and toss a pot of water on the stove. hook a wire between both and use some pliers to hold the sensor end of the sender in the water as it comes to temp, you should see the gauge sweep across its motion as the water heats up to boiling.

most basic test you can do for a temperature sender and/or gauge.

this way you can completely isolate and test them in a controlled environment.

 

[daydreamer1252]

Re: running hot

stackz.....at the stove without 12v dc or ground connection?? Doesn't sound like a plan to me!!

And imraan when you try the new wire be sure to disconnect the OLD wire from the back of the gauge....

 

[stackz]

Re: running hot

stackz.....at the stove without 12v dc or ground connection?? Doesn't sound like a plan to me!!

And imraan when you try the new wire be sure to disconnect the OLD wire from the back of the gauge....

the 12v and ground are for the backlighting normally. sender is based solely off of ohm reading. maybe different for boat gauges vs. auto though for all I know as I'm still learning the subtle differences between marine/auto systems. so many tiny little details and we all know the devil is in the details.

 

[daydreamer1252]

Re: running hot

stackz.....no electricity...no OHMS....your proposal won't work....fine for testing a thermostat....but without a power source the juice for a temperature gauge to measure won't be there.....measure the resistance cold with an VOM and then heat it and measure again see if it changes.....I'll buy that....otherwise no.........your on the wrong page or something.....

 

[stackz]

Re: running hot

stackz.....no electricity...no OHMS....your proposal won't work....fine for testing a thermostat....but without a power source the juice for a temperature gauge to measure won't be there.....measure the resistance cold with an VOM and then heat it and measure again see if it changes.....I'll buy that....otherwise no.........your on the wrong page or something.....

you're right. I stand corrected. I guess thats what I get for trying to goof around on the internet while talking with a client on the phone and doing two spreadsheets at once. dont get much time for critical thinking

but yeah, I looked up a diagram online because I was second guessing

in the end, its not that hard to toss the battery on some cardboard on the counter...

 

[cr2k]

Re: running hot

I think the original question is of the physical heat on the riser. How soon we get side tracked....

Could be riser is in need of internal cleaning or replacment. It matters not what the gauge reads if the riser is too hot to touch. Things are too hot. If it one and not both; probably rusted and partially plugged or thermostat housing rusted.

 

[rickryder]

Re: running hot

This is very true cr2k.... I was just addressing the inop gauge It would be nice to know if it's running hot and causing the hot riser.

 

[imraan47]

Re: running hot

I think the original question is of the physical heat on the riser. How soon we get side tracked....

Could be riser is in need of internal cleaning or replacment. It matters not what the gauge reads if the riser is too hot to touch. Things are too hot. If it one and not both; probably rusted and partially plugged or thermostat housing rusted.

so at the ramp first thing i did is take the wire of sender...guess what...guage reset back to cold. i put the wire back on the sender and its sitting at cold now.

So far what i have done is checked the thermstat again. i see that the housing does have enough brown/rust but nothing is clogging it from what i can see.
i am not sure but i guess for me to clean the risers or to even check in there the engine might have to come off???
some of the wires thats taped that run around the top of the engine on starboard side is kinda melted..its just the electrical tape thats melted a little in some spots. so this is not a good sign for me. i am sure i have overheating problems at this point.
otherwise i still ran the boat and no problems but things can be getting worse somewhere.
i have the old sender here and going to test that first in boiling water. will post back on results of that. i cant find my socket set to take the one thats on there right now and test that but im sure thats fried.

 

[imraan47]

Re: running hot

ok so tested the old sender that was on the boat.
the resistance with the ohm meter was going lower as the water was boiling. then took the sender out of the water and the resistance was going back up slowly as the sender cooled down.
so this sender is working fine.
now i am thinking that i perhaps got the wrong sender. when i bought it, the shop matched it based on the engine i have. but the new sender was alittle different looking than what was on there in the first place. the new one was smaller looking. so anyhow i think i will put the old one back and see what happens.

 

[imraan47]

still no luck

still no luck

ok still no luck with this and its pissing me off.
tested the darn sender and it works..put that one in (the original one) and with a new thermstat....
guage still wont work

i unpluged wire going to sender through harness and just used a spare wire i had to go from guage to sender and still guage wont move...its reading cold.

please help...as the darn rises and block feels really hot to me....i need this guage working anyway.