wildbill Posted December 18, 2013 Report Share Posted December 18, 2013 Hi. I am wondering if any electrical experts out there can help me with a little problem. I have dragged my 1993 GT32 Contact 327 out to check it over ready for what is generally its only outing of the year. Due to several other bikes being available it doesn't see the light of day very often and only gets started every couple of months or so. As the original Motoplat system has been replaced by a later Kokusan set up, starting is rarely a problem. Due to a faulty thermostat (type that screws directly into the head) when I bought the bike, I wired it to be permanently on some while ago. No problems - until today. Started up as usual but no fan! Tried flicking fan to see if it was sticking but no joy. Turned engine off and flicked fan and it spins freely. Connected fan to a battery and it spins up OK. Only other thing I noticed is with the engine running, the fan seems to be 'energised' and actually resists being turned. Turn engine off again and it will spin quite happily with a flick. Could this be a sign of a failed rec/reg? Any ideas or comments gratefully accepted (except stick the bike in the bin and get a new one!!) Bill Quote Link to comment Share on other sites More sharing options...
lineaway Posted December 18, 2013 Report Share Posted December 18, 2013 Off hand I have no solution, but since it runs check the power coming to the fan as a starting point. Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 18, 2013 Author Report Share Posted December 18, 2013 Hi lineaway. Thanks for the quick response. Excuse my electrical ignorance but in order to test the power going to the fan do I just put the leads of a multimeter across the 2 fan motor wires with the engine running and would I then expect to see a reading of around 12v DC? Bill Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 18, 2013 Report Share Posted December 18, 2013 You should be getting 12 volts to the fan wires with the bike running. It would be best to check the wires with the fan disconnected. I suspect you are getting low voltage from the description. Check all the connections and grounds. Better yet, take them apart and clean them with abrasive paper to remove any oxidation. Metal bits should be shiny for good connection. And don't bin it! Get on the pegs and ride! Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 19, 2013 Author Report Share Posted December 19, 2013 Hi that's_a_five Just checked voltage across fan feed wires with engine running at tickover and its 26.5v. Presumably this means that regulator is not working correctly as the feed should only be around 12v? Bill Quote Link to comment Share on other sites More sharing options...
lineaway Posted December 19, 2013 Report Share Posted December 19, 2013 Interesting that at that voltage it does not spin. http://www.gasgas.co...an-96-2000.html Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 19, 2013 Author Report Share Posted December 19, 2013 Just spent some time replacing a few suspect connectors and rigging up an additional earth from engine casing to frame and retested electrics. Still getting a reading of 26 - 27v across fan feed wires when engine is running and fan is disconnected. When engine is running and fan is reconnected I am getting a reading of only 6v across the fan feed wires?! Bill Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 19, 2013 Report Share Posted December 19, 2013 Wow, 26 volts. Good that you fixed any connector or ground problems. There are 2 items that might be problems. 1) the Voltage regulator may have failed. Sorry I don't have my Gasser any more so can't check voltage for you. Wiring diagram shows 12 volts. 2) the rectifier that converts Alternating current (AC) to Direct Current (DC). I suspect it is the rectifier. That item converts AC to DC and usually drops the voltage about half. Check the fan voltage on both the AC and DC scales on your meter. It should only read on DC. Bill Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 26, 2013 Author Report Share Posted December 26, 2013 Hi. Did a bit more work on the wiring leading up to Christmas. Checked voltages across feed wires to fan again following changes to connectors and cleaning terminals. With engine on idle, got readings of 26V DC and 4.5v AC! Don't know whats happening there! In the end I cleaned the terminals again and cut back some of the wires that appeared to have corroded inside the plastic insulation and fitted new connectors. Tested again and got 27V DC and 5.7v AC this time! In a fit of frustration I connected the fan wires the other way round, started engine and hey presto - working fan again! The fan even turns over now just by turning engine over on kickstart! Electrics - don't you just love em!!! Thanks for all replies Bill Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 28, 2013 Report Share Posted December 28, 2013 I am glad it is working but I wonder how long that fan will last at 27 volts. There is little doubt in my mind that the rectifier has gone bad. I would encourage you to replace that before the fan fails far from your truck, leaving you with an overheated bike and a long push. You should be able to replace it with an OEM part or a "rectifier bridge" that you can get at an electrical store. See if you have a friend who knows electrics who can help you get it wired up right. 1 Quote Link to comment Share on other sites More sharing options...
tltel Posted December 28, 2013 Report Share Posted December 28, 2013 Is The fan spinning the right direction? TLTEL Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 29, 2013 Author Report Share Posted December 29, 2013 Hi TLTEL - The fan will only work in one direction. If I connect the motor feed wires the other way the fan motor will not turn, it just seems to become 'energised' and resists being turned in either direction with my finger. That's a five - Think you may be correct. I have bought a cheap rectifier as suggested by a post on this forum @Cheap rectifier replacement'. I will try to find some time to wire it up now that I have got Christmas out of the way. Bill Quote Link to comment Share on other sites More sharing options...
tltel Posted December 30, 2013 Report Share Posted December 30, 2013 Is it blowing or sucking?? TLTEL Quote Link to comment Share on other sites More sharing options...
thats_a_five Posted December 31, 2013 Report Share Posted December 31, 2013 Is it blowing or sucking?? TLTEL Kinda depends on which side of the radiator you are on. Actually the radiator does not care which way the air is blowing so would be fine when the bike is not moving. Could be a problem if it is blowing toward the tire when the bike is moving forward. WildBill - let us know how it turns out. Quote Link to comment Share on other sites More sharing options...
wildbill Posted December 31, 2013 Author Report Share Posted December 31, 2013 Hi TLTEL. Checked the fan again today and when sat on the bike the fan is rotating clockwise. I tried to sort out whether it is sucking or blowing by placing a piece of tissue paper close to the joint of the fan mounting to radiator and it appears to be blowing. To be fair, I have never really noticed which way it ran prior to this problem and as I said in my earlier post the fan will not run with the connecting wires reversed. The fan is a little noisy (it is 20 yrs old!) but does spin at a fair rate. Maybe there is a problem with the fan motor too as I have a spare Honda 125 fan motor and that happily spins in either direction depending on how wires are connected Bill Quote Link to comment Share on other sites More sharing options...
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