Cooling Fan problem, Help!

well I was out working on the VFR today, I recieved some more parts. One thing I got was a new fan switch because my fan was not working, I noticed this a couple of weeks ago. Anyway I replaced the fan switch and it does still not work.
I bypassed the fan switch with an extra battery I have, with tester leads, and the fan runs/works. Does anyone know, possibly, where the hot/ live wire goes from the fan. I was able to trace it as far as the wire harness connector, as for the ground also, but I dont know where it goes from there. I am assuming it is either a bad ground or its not getting juice.
I have to go and get me a multimeter in the morning, is there a way to check for juice going anywhere to the fan without the bike running? Or how would/ could I check for juice getting as far as the fan switch or before?
I know its probably not a good idea to hard wire the fan to "on" all the time. Would it be possible for me to rewire the system easily?

 

Dan, the standard check is to short the wire that plugs into fan switch to ground (with key ON) ,and fan should run.

IF fan won't run, check fuse and plug-in for fan on right side electrical panel located under plastic panel under right handlebar area.....there is also a ground wire from fan to the shroud mounted on radiator which must be working.
Inside the fuse box, the fan is controlled by the second fuse from the left.

Many use a manual fan switch running between ground and the wire that plugs onto factory switch, but don't have fan running always, only when temp is high......

 

K I did the test, and checked the connector and fuse. All is plugged in and fuse is good, has connection between terminals inside. The fan did not turn on doing the test so.....? the ground wire that goes from the fan to shroud visible from where? I cant find that one.

 

check and make sure you have power at the fan. easiest way to do that is just unplug fan switch connector and use a voltmeter if you have one. you should have battery voltage with the key on. if thats good check your ground. you can either visually check it or use an ohm meter and go from where the senor screws in and to the negative battery terminal. there should be very little resistance. if it high you probably got a dirty connection. i hope this helps, im not really familiar with year but going with what i have read on this thread it should be correct diagnosis

 

is the fan switch activated by creating ground or is it hot?

 

V4Dan... do you have a voltmeter or an auto idiot light (looks like an icepick with a wire coming out the handle with an alligator clip on the end)?

Either of these will help answer your question and be used to diagnose the problemo.

- Paul

 

by the way squirrelman described his test the circuit should work like this:
with the key on voltage is fed through the fuse down the wire to the fan motor and through the fan motor windings where it sits waiting for the fan switch to make contact internally which creates a ground for the power and turns the fan on. (man, talk about a run-on sentence) now if you unplug the connector for the fan switch and turn the key on you should have apprx. battery voltage. any less would indicate resistance in that part of the circuit causing a voltage drop and not allowing enough current through the wiring to turn the fan on. this is all providing the fuse is good, which you said you checked. i looking in my honda manual and this is the way my bike is wired, its a 97 but i would think the have not made much change to the wiring. its a pretty standard way of wiring a cooling fan. if you have good voltage then you need to check the ground. but i think you tried shorting the ground and the fan still was inop so i think your looking at a power supply issue

 

K, Thanks guys Im gonna get back on this issue in the morning with a voltmeter. I hate electrical problems, Im good mechanically for the most part, but electrical drives me nuts. I think this is my last electrical issue to deal with.

 

I hate electrical problems on old bikes. A guy is never sure whether some prior owner had a better idea about wiring things up. Gad!

 

V4D, I live in Trooper,Pa about 20 miles from Boyertown. If you are off this Monday we could meet and I could take a look at it. I am reasonably proficient with wiring. If you can download a wiring diagram that might help.
eddie

 

Thanks eddie, I have to work on monday. but I get home @ 3:15pm everyday., not sure how this would work for you. Im gonna run over to a friends place today before the race and grab a voltmeter, but hes not edumacated on bikes.

 

O.K. I think VFR750Rider nailed it. I checked the system with a voltmeter. There is no power to the fuse for the fan with the ignition turned on. Now that I think about it though my kill switch was in the off pos. though., but I dont think that matters. I checked all of the connections again including the ground on the radiator itself which I did find, it was a little burried in there, top right corner of the rad. and shroud. Anyway I think it is a power supply issue. Is it possible for me to bypass the original fuse and run a new hot wire with an in line fuse to the wire harness that supplys the fan still using the thermostatic switch? I also checked the power relay, but all seemed to be fine there, everything else electrical works.

 

On my 700, the PO had replaced the ignition switch from another bike. My fan gets it's power through the ignition switch. The problem was the model of my ignition switch did not have that connection!

The slot was there, but no copper connection. I soldered in a jumper wire from another ignition wire and made the connection.

Use your circuit diagram to find out where your fan's power is supposed to come from. Also, check it with the engine running. Some components don't work with the engine off - so it's hard to test for electrical power.

You trouble shoot electrical problems from either the device back to the battery, or the battery to the device. I find it's usually easier to start with the device back to the battery - as you are doing.

 

i looked at my wiring diagram and it looks like power comes right off the ignition switch then to the fuse so i think mason v45 is on the right track withthe ignition switch problem. if this is just a recent problem without the replacement of an ignition switch in the past it might be internal in the switch.
in which case you would need a new switch. i really wish i could see a wiring diagram for that year so we could nail this down . but the switch theory makes sense, think how my times that ign. has ben turned on and off. also according to my diagram the kill switch should not affect the fan circuit.

 

Thanks for everyones help, I havent been able to find the culprit yet but the next thing Ill do is check for power supply from the ign.sw. If I cant find the power source think Ill just run a new one myself to the harness using an in line 10a fuse. I beleive the fan switch should still work for me if I do it this way, if not nothing gained but nothing lost. Im just not sure of where I should run my new line(if thats what I have to do)from. I would just like power to it while the ignition switch is turned on or the bike is running. I dont have the time during the week to work on the bike, so I cant do any thing to it till the weekend

 

I want to post that I have found the culprit and the fan works, got power to the fuse and lead wire off the switch, there was a wire harness Not connected at all near the harness that supplys the fan wire harness, It was a little hidden from my view. Guess Im gonna have to go over the whole bike with a fine tooth comb, aye yi yi!

 

Yep. you might want to (stomp foot) go through stuff with a fine tooth comb now that you've confirmed someone has fixed things by disconnecting them.

Do you have a wiring diagram for your bike?

If not, you'll want one. Then you will help yourself tremendously if you trace the wires and highlight them on the diagram, each of them,

a) do they go where the diagram says they go?
b) do they ground to the chassis? (if they are not supposed to.)

Since it seems someone prior to you unplugged some stuff they likely had a reason. You'll get to be Kojak and figure it out.

If you high light the diagram as you go, you'll know your bike's electric system much better and may be able to diagnose the problem(s) you've been having.

Do you know how to do this Dan?

 

NO, I dont have the diagram, or really know to do this but it, doesnt sound fun. I already had to replace the horn, and headlight bulb, these didnt work either, but It may have been from this problem, they all may have gotten power from this harness that was disconnected, I hope. I guess Ill have to get me a manual, Im overdue for one. Do u know of a source that I could get this diagram for free?

 

Dan: found this old thread. I went to the early honda v4 bulletin site, but there is only an e-mail at the bottom. I'd send a note asking for the diagram, he had them, just likely did not want to get into trouble for posting them online. also could pm the dudes in the thread, or post up a question asking for the wiring diagram for your bike. You'll *really* want that if you are having issues with the bike, oh my - you are :wink:

http://vfrworld.com/forums/modifications/6582-ammeter-bike.html

good luck, -Paul