OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
I've noticed lately that when starting the engine, even when the temperature is right at freezing, the cooling fan runs wide open. Turn the key hear the whine.

Before I go buy a temp switch (temp sending unit)part 584676; I would just like to run this by you guys to see if this is indeed the cause. Or could this possibly be some other issue.

Thanks in advance.
@jkj-fz6 avatar
UTC

Ossessionato
BV400, Primavera 150, Yamaha Zuma 125
Joined: UTC
Posts: 4224
Location: Twin Cities, Minnesota
 
Ossessionato
@jkj-fz6 avatar
BV400, Primavera 150, Yamaha Zuma 125
Joined: UTC
Posts: 4224
Location: Twin Cities, Minnesota
UTC quote
I would test the temperature switch with a meter before I bought another one. If the switch is closed when the engine is cold, there's the problem. Switch is bad.
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Good idea testing that thing.

Also wonder if it could be the coolant temperature sensor part#82622R sending the wrong info.
@wbdvt avatar
UTC

Molto Verboso
'16 Sprint S 150, 2 x '06 GTS 250, '12 GTS 300, '74 Vespa 150 Super
Joined: UTC
Posts: 1416
Location: Vermont
 
Molto Verboso
@wbdvt avatar
'16 Sprint S 150, 2 x '06 GTS 250, '12 GTS 300, '74 Vespa 150 Super
Joined: UTC
Posts: 1416
Location: Vermont
UTC quote
Could also be bad connection. Just went thru this on a GTS 250. Search postings

Unplug temp sensor and see if fan still runs. That could eliminate a bad fan relay

If like the GTS 250 there are 2 sensors in that one element. One goes to the dash indication the other to ECU to control fan. If you measure the resistance of each sensor they should be the same
@jkj-fz6 avatar
UTC

Ossessionato
BV400, Primavera 150, Yamaha Zuma 125
Joined: UTC
Posts: 4224
Location: Twin Cities, Minnesota
 
Ossessionato
@jkj-fz6 avatar
BV400, Primavera 150, Yamaha Zuma 125
Joined: UTC
Posts: 4224
Location: Twin Cities, Minnesota
UTC quote
tazmo wrote:
Also wonder if it could be the coolant temperature sensor part#82622R sending the wrong info.
My bets are on the switch. The temp sensor would be sending the temperature to the ECU (and the temperature gauge if the GT200 has one), but I don't think it directly controls the fan.
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Yes this model has an analog temp gauge on the dash. It runs cool and has never overheated and after setting a few months noticed that fan coming on when the ignition key is turned on with a very audible whine.
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14754
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14754
Location: The state of insanity, SoCal
UTC quote
a quick check is to pull the temp sensor connection and see if the fan stops. I would also check the resistance on the sensor.

more likely is that the fan switch has failed, or less likely the fan relay itself.

but I'd check for any loose wires first before buying parts.
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Thanks Greasy....good idea.
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 43408
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 43408
Location: Pleasant Hill, CA
UTC quote
The temp sensor on the GT200 is nothing to do with the fan - the fan is purely controlled by the thermal switch inline with the hoses - or on the LH radiator, I forget which.

One side of the fan is permanently at +12V, the other goes to ground via the thermal switch.
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Thanks for that heads up.
Noticed in the parts diagram that the sensor did look like it was inline with the radiator hose. Well I bit the bullet and ordered both from ScooterWest just to be on the safe side and my luck when torn down it'll be a loose wire. The ole girl has held up fairly good and usually it's a lose connection or a hose that went bad losing suction or some such.
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 43408
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 43408
Location: Pleasant Hill, CA
UTC quote
One thing I don't understand is the fact that the fan only runs when the ignition is on - or is it when the engine is running? On the GT200, the fan 12V feed is on permanently, and if the bike overheats the fan will stay running with the engine turned off, until it's cooled down. Perhaps someone has added a relay or somesuch?
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14754
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14754
Location: The state of insanity, SoCal
UTC quote
jimc wrote:
The temp sensor on the GT200 is nothing to do with the fan - the fan is purely controlled by the thermal switch inline with the hoses - or on the LH radiator, I forget which.

One side of the fan is permanently at +12V, the other goes to ground via the thermal switch.
thanks for the correction Jim, I was having a moment there.

thermal switch is inline with the hoses on the RH side just below the radiator.
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Everything runs normally there is no overheating. The fan runs constantly the moment the bike is switched on, starting, and while running under normal loads.

As we all know the fan kicks in when it hits a thermal setting to keep cool, but this was a new one, hearing that whine while starting or even switching it on to start the start process even when the temp is below 32 degrees and has been sitting and cold as a witches titty. Even here in the deep South...brrr.
⬆️    About 27 days elapsed    ⬇️
OP
@tazmo avatar
UTC

Hooked
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
 
Hooked
@tazmo avatar
2007 GT 200L
Joined: UTC
Posts: 214
Location: S C
UTC quote
Found out the reason for the fan auto on AND the headlights were intermittently going off and on was, after taking the assembly apart to change headlight bulb, noticed a red multi-wire connector on the back side of the speedo/dash, was not quite 'snapped' in properly. Pushed that in and changed the LED bulb while I was there and everything went back to working properly.

So all the folks saying check for loose wires (and or connections) was spot on.
DoubleGood Design banner

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Buy Me A Coffee
 

Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com


All Content Copyright 2005-2024 by Modern Vespa.
All Rights Reserved.


[ Time: 0.0249s ][ Queries: 3 (0.0027s) ][ Debug on ][ 313 ][ Thing One ]