Thermo switches

[rbjohnsn]

Looking for help on the location of the fan thermo switch. There are three listings in the schemtics (#31,#40,#68). I'm not sure where the location of the fan (item # 31) is. From what I can tell looking at a pictorial drawing for the part location I've found #40, which is for the carb heaters, which is behind the Right cheek panel. Number (#68) looks to be for the ideat light and its location is on the thremostat block. Question is where is #31 located.

 

My fan has never comes on. I ride in very hot weather, but never heard the fan operate. I've been able to figure out the fan works plus the filter by connecting 12 volts to the connectors. So far I've not been able to find the third thermostat #31.

 

Is there anyone out there that can help retain my hair. There are so many errors in the drawings it has become a hunt and peck situation.

 

Any help would be greatly appreashated.

[Sylvester]

Why worry? My fan has only come on once and that was while idling in the hot afternoon. When you are riding they hardly ever come on. My 81 Goldwing was the same way.

[V7Goose]

I do not know the location, but it must operate off a signal from the temp sensor, the same for the overheat light. The fan plug is behind the left lower fairing, so I'd try to trace the wires back from there or forward from the temp sensor. Since you say you have tested the fan, I am assuming you already know where those components are and have not had any luck following the wires, and I am sorry I cannot give you more specific guidance. I just wanted to let you know the fan trigger probably won't look anything like the carb heater thermo switch since it does not operate off the ambient temperature.

 

But I would not be so sure your fan is NOT coming on. It is very quiet, and for the first year I owned my RSV I never noticed it. I can tell you for certain that it will come on quite often any time you are not moving, even in mild temperatures. I do a lot of carb syncs for other members, and I have never had one NOT come on before I got done. Well, that is not completely true . . . About a month ago I was doing a sync and started getting a little coolant from the overflow tube - we looked and the overheat light was on! Turned out something was jammed down in the fan, preventing it from turning, so it had been triggered, but without the air flow from the fan at idle, the coolant got hot enough to trigger the idiot light and boil over to fill the overflow tank and start dumping.

 

As I said before, the fan is pretty quiet. I can hear it if I listen specifically for it while just sitting on the bike, but even when I am doing a sync I usually only notice the sudden blast of hot air and not the sound of the fan. Since I have a temp gauge on my bike, I can tell when the fan comes on just by the engine temp, but I sill never notice it unless I specifically look at it or put my hand down by the side of the engine to feel the air. The fan is triggered somewhere around 230 F, and neither of my RSVs have ever reached that temperature while normal riding. But they will do it fairly quickly at a long light or stop-and-go traffic. You can get a fairly accurate water temp reading with an IR thermometer by aiming it at the water jacket around the side of one of the rear spark plugs (one with a laser pointer to aid in accurate pinpoint aiming is needed). A safe test is to watch the engine temp that way while you let the bike idle. Or just let it idle until either the fan or overheat light comes on. If the fan is not working and it does get hot, you won't hurt anything if you shut it down when the light comes on.

Goose

[KiteSquid]

I had to let my bike idle for about 10 minutes before the fans ran.....

[rbjohnsn]

I do not know the location, but it must operate off a signal from the temp sensor, the same for the overheat light. The fan plug is behind the left lower fairing, so I'd try to trace the wires back from there or forward from the temp sensor. Since you say you have tested the fan, I am assuming you already know where those components are and have not had any luck following the wires, and I am sorry I cannot give you more specific guidance. I just wanted to let you know the fan trigger probably won't look anything like the carb heater thermo switch since it does not operate off the ambient temperature.

 

But I would not be so sure your fan is NOT coming on. It is very quiet, and for the first year I owned my RSV I never noticed it. I can tell you for certain that it will come on quite often any time you are not moving, even in mild temperatures. I do a lot of carb syncs for other members, and I have never had one NOT come on before I got done. Well, that is not completely true . . . About a month ago I was doing a sync and started getting a little coolant from the overflow tube - we looked and the overheat light was on! Turned out something was jammed down in the fan, preventing it from turning, so it had been triggered, but without the air flow from the fan at idle, the coolant got hot enough to trigger the idiot light and boil over to fill the overflow tank and start dumping.

 

As I said before, the fan is pretty quiet. I can hear it if I listen specifically for it while just sitting on the bike, but even when I am doing a sync I usually only notice the sudden blast of hot air and not the sound of the fan. Since I have a temp gauge on my bike, I can tell when the fan comes on just by the engine temp, but I sill never notice it unless I specifically look at it or put my hand down by the side of the engine to feel the air. The fan is triggered somewhere around 230 F, and neither of my RSVs have ever reached that temperature while normal riding. But they will do it fairly quickly at a long light or stop-and-go traffic. You can get a fairly accurate water temp reading with an IR thermometer by aiming it at the water jacket around the side of one of the rear spark plugs (one with a laser pointer to aid in accurate pinpoint aiming is needed). A safe test is to watch the engine temp that way while you let the bike idle. Or just let it idle until either the fan or overheat light comes on. If the fan is not working and it does get hot, you won't hurt anything if you shut it down when the light comes on.

Goose

 

The maintance manual says to remove it thermo switch from the radiator, but with everything so congested in that area its hard to see. The diagram is only showed on the electrial drawing and not the mechnical.

[rbjohnsn]

Why worry? My fan has only come on once and that was while idling in the hot afternoon. When you are riding they hardly ever come on. My 81 Goldwing was the same way.

Why worry!

I live in the deserted. Try being stuck in traffic when it is 120 deg. California has a filter law allowing an air cooled engine bike to split the traffic, but if is water cooled, the split traffic law does not apply. Arizona on the other hand does not have that law, as many states. Its nice the Venture has water cooled engine. The fan will help keep the engine from destoying it's self under those condictions.

[V7Goose]

The maintance manual says to remove it thermo switch from the radiator, but with everything so congested in that area its hard to see. The diagram is only showed on the electrial drawing and not the mechnical.

Based on this comment and a quick look at the shop manual, it does seem as my assumption on what triggeres the fan was wrong. From what I can tell, the "thermo unit" seems to be mounted just to the left of the filler neck at the top rear of the radiator. But the "thermo unit" is the high temp sender. The manual states the "thermo switch", which controls the fan, is mounted in the thermostat housing. Of course, the manual just MIGHT have an error - there are one or two in it! The identifying key would be how many electrical connectors are on each "thermo thingie" If it is just one, it is the high-temp sending unit. If it has two leads, it is the fan switch. Hope you find it.

Goose

Edited June 11, 2009 by V7Goose
adding details

[rbjohnsn]

Based on this comment and a quick look at the shop manual, it does seem as my assumption on what triggeres the fan was wrong. From what I can tell, the "thermo unit" seems to be mounted just to the left of the filler neck at the top rear of the radiator. But the "thermo unit" is the high temp sender. The manual states the "thermo switch", which controls the fan, is mounted in the thermostat housing. Of course, the manual just MIGHT have an error - there are one or two in it! The identifying key would be how many electrical connectors are on each "thermo thingie" If it is just one, it is the high-temp sending unit. If it has two leads, it is the fan switch. Hope you find it.

Goose

Thanks for the effort.

I found it about 7 hours ago, and as you said its on the top leftside of the radiator. Since then I've tried to remove the connector so as to short the two pins and confirm the hole circuit, minus of course the thermo switch, BUT leave it to those small handed people there is know way for my big hand to disconnect the connector without removing the radiator. Even made a special tool to grab the connector only to find out 6 hours later there is a locking clip on the backside from my view. Had to use a dental mirror to detect it. There just is know way to compress the clip and push back the connector off while the radiator is installed for me. I wonder what the flat rate is on testing the cooling system! LOL.

Your also correct on the ERROR's within the drawing. Normaly I can follow a schematic. I spent most of my life in electronics. The Japanise electrial schematics / drawings suck. The mechinal on the other hand are great for the most part.

I'll just half to run the engine, till it gets hot and see what happens with the fan.

[boominup]

My fan has never comes on. I ride in very hot weather, but never heard the fan operate. I've been able to figure out the fan works plus the filter by connecting 12 volts to the connectors. So far I've not been able to find the third thermostat #31.

 

You've not mentioned if your "high temp" light comes on. If it doesn't, and the light is operational, you are probably chasing after ghosts since the fan is so quiet. This bike of mine had me worried when I first got it cause I'd never hear it kick in. Only after I synced my carbs for the first time did I hear it. I don't worry about that anymore since your bike will self diagnose the lights and systems, I think. Just let it idle for about 10 mins and keep a close ear. I'm willing to bet it works. Brian

[rbjohnsn]

My fan has never comes on. I ride in very hot weather, but never heard the fan operate. I've been able to figure out the fan works plus the filter by connecting 12 volts to the connectors. So far I've not been able to find the third thermostat #31.

 

You've not mentioned if your "high temp" light comes on. If it doesn't, and the light is operational, you are probably chasing after ghosts since the fan is so quiet. This bike of mine had me worried when I first got it cause I'd never hear it kick in. Only after I synced my carbs for the first time did I hear it. I don't worry about that anymore since your bike will self diagnose the lights and systems, I think. Just let it idle for about 10 mins and keep a close ear. I'm willing to bet it works. Brian

 

Brian, such a trusting sole.

The high temp light does work, but it's not automatic when starting the engine as are the other functions. You need to activate the kill switch, be in netural, or have the clutch disengaged while trying to start the engine at which time the RED temp light activates.

Frankly there is a ghost. When first applying current through the electonic fan filter the fan was motionless. After removing some electrial tape wrapped around the two wires which comes from the thermo switch, located in the radiator, the fan worked, and no longer could I make it fail. BUT, that was with the harness exposed and out in the open. To make sure everything will function after putting things back into place it can only be comfirmed to function is by shorting the two pins at the thermo switch.

I don't mean to such a pain but I've worked as a tech and engineer in electronics for 45 years. Never assume! It could be a costly mistake.