Honda Shadow Forums banner

1 - 20 of 45 Posts

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #1 ·
So, i recently pick up a '89 VT600. I rode it a few times with no problems whatsoever. Me and my buddy went on a cruze, not far maybe about 25 miles one way. On the way back we hopped on the freeway, maybe going about 60-65 MPH for about 5 miles. i noticed my temp light came on. we pulled over and sat there for a bit to let it cool down and continued on our way home (had to stop a few times). Finally made it home. I let my bike cool down then i went to check the coolant; bone dry. Also noticed coolant dripping down the radiator, i inspected that and found the previous owner did not have a(n) overflow tank, therefore i'm pretty sure all the coolant drained thru the tube onto the street. I custom made and overflow using a monster can for temporary use. I added coolant, burped the system hoping that was the issue. Yesterday me and my buddy wanted to take a cruise to the beach, got about 20 min away from home, noticed temp light again. We got off the freeway let the bike cool and just went back to my house from there. Today i brought my bike to work, did not over heat due to cold morning weather but on my way home it was about 90 degrees out and the temp light was on once again, but this time i noticed coolant on the top of the #1 cylinder and also see dried coolant leaking down the thermostat. I did the bridge test on the cooling fan (i really don't know if i did it right) and the fan never came on. I also just ordered a thermal switch for the fan but hasn't arrived yet.

Can anybody give me any advice since this is my first bike and i really have no clue as to what i'm doing. Youtube doesn't help much for diagnosing bike issues
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
If you ground the black wire from the fan motor to the thermo switch with key on it should run.
Maybe a fuse has blown for the fan? It has a dedicated fuse in the fuse box.
 

Attachments

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #3 ·
Thank you for your reply! Now i'm a little confused tho. is the thermo switch the wire coming off the bottom of the thermostat housing or the switch at the bottom of the radiator? Sorry new to this motorcycle repair thing.
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
The fan control thermo switch is on the bottom of the radiator.
The one on the thermostat housing is for the temp gauge, or light.
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
Something to check also is if the radiator has to be grounded if it is the one wire style thermo switch. If it has been off before, it may not have it's short ground wire connected to the frame - or it is corroded.
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #6 ·
yes its a one wire style thermo switch. Where would the ground wire be located on the frame? up by the bar above the radiator
Something to check also is if the radiator has to be grounded if it is the one wire style thermo switch. If it has been off before, it may not have it's short ground wire connected to the frame - or it is corroded.
yes its a one wire style thermo switch. Where would the ground wire be located on the frame? would it be on the thermo switch wire or does it have its own location from the fan motor? does it lead up by the bars above the radiator and connect to the frame there? i tried following the thermo wire and i just lose it. cant seem to find where it leads without removing the radiator.(which i probably have to do anyways). could coolant be leaking from the coolant temp sensor on the thermostat? its not alot of coolant leaking but after every ride i notice fresh coolant on top of the engine(little droplets all over the cover) or could the sensor be reading wrong? <-- regardless i'm still loosing coolant somewhere
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #7 ·
I don't want to keep buying parts and just hope that's the problem as some parts are pricey!
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
I saw a picture of it one time that showed it up on the left side. I think a short wire from a radiator bolt to the frame. You can always add a ground to any circuit if it is a problem just a wire to the frame bolts. Easy to test with a wire as a temporary ground to see if it works.
My bike is a 2 wire sensor so it doesn't have it that way.
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
For the leak,wash it off with water and dry it and see if the top radiator hose needs a clamp tightened. Or other hose up there.
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #10 ·
293850
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
I would start looking at the gasket O ring for the thermostat housing cover.
And loosen that spring clamp on the hose to the left and rotate it around a little to give it a new grip.
 

Attachments

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #12 ·
I would start looking at the gasket O ring for the thermostat housing cover.
And loosen that spring clamp on the hose to the left and rotate it around a little to give it a new grip.
thanks for your help! that little bit of drip would cause overheating correct? or no?
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
If it lowers the radiator level it will cause over heating. Probably a constant drip as you ride.
Especially if the radiator cap is not sealing well and the fluid in the over flow tank doesn't get pulled back into the radiator, many guys say well "the tank has fluid in it". The radiator has to stay full.
 
  • Like
Reactions: CSRoad

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #14 ·
If it lowers the radiator level it will cause over heating. Probably a constant drip as you ride.
Especially if the radiator cap is not sealing well and the fluid in the over flow tank doesn't get pulled back into the radiator, many guys say well "the tank has fluid in it". The radiator has to stay full.
Understood. I will take your advice and check the fuze for the fan motor, check the O-ring for the thermostat, re-adjust the coolant hose for better grip, and check the ground for the radiator! i really appriciate your help, and ill update this thread once i complete these tasks! Thanks again!
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #15 ·
@swifty2014 So i replaced my thermostat and housing with a used one from ebay. Ended up still leaking. So i made a gasket using some gasket maker. shes all sealed up and so far so good without overheating or leaking! All new hoses, rad cap, thermal switch and ect sensor. Thanks again for you help swifty i appreciate it !
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #16 ·
@swifty2014 She did it again sadly... its sputtering now at hwy speeds when i throttle to get around vehicles. You think overheating is cause from a lean condition?
 

·
Registered
1983 Honda vt750 Shadow
Joined
·
16,207 Posts
If you keep your radiator full and the fan is working it should be Normal temps.
Did your burp it well to make sure the radiator was totally full?
Look at the color of the spark plugs they may show very white if it is running too hot.
Is your air intake system still factory stock?
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #18 ·
Yeah i burped it to make sure it was full to the top by leaning and rocking the bike back and forth and adding more when it went down, until it didn't. As for fan, i bypassed the thermoswitch and the fan works but i never hear it come on or see it come on when temp light is on. ill check the plugs today. a normal operation would have the plugs a light brown color correct? As for air system im running stacks on my dual carb. Although its not overheating like it was, now all i have to do to get the temp down is lower my speed to about 55 and coast once i throttle even a little bit it comes back on.
 

·
Registered
2001 Valkyrie I/S
Joined
·
6,168 Posts
If the fan isn't coming on when the engine gets hot and it runs if you bypass it you have a bad thermal switch.
 

·
Registered
1989 Honda Shadow VT600C
Joined
·
62 Posts
Discussion Starter · #20 ·
I just replaced it with a new factory OEM honda part
 
1 - 20 of 45 Posts
Top