Radiator fan and tach issue.

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82300r

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folsom, la
Early this summer I was well on my way to working lots of bugs out of my 86 v max. Carbs rebuilt. Exhaust change. Plug wires. Etc.. Had it running wonderfull. Was on my way to tackle the 'Hot Start" Problem. Then the voltage regulator fried. No big deal but got busy with other things an put the bike up. Fast forward. Ordered a new regulator an got the " gold wing battery mod". Got It all installed. Fresh gas. Checked spark plugs. BLA.BLA.. Cranks up fine hot or cold. Looked like mission accomplished ! WELL, now the tachometer does not work AND the fan will not kick on. Temp guage works cluster lights etc. Let the bike run well into the red an coolant starting to bubble in tank. No fan. Shut it off. Cools down quickly. Cranks right up HOT. No problem. Tach? Huh, I.D.K. Never had this problem before. Could it have something to do with what I did? Oh and yes checked all fuses. ALL look good. Gonna sleep on it tonight an go over it again in the a.m. Any ideas??? An the bike only has a little over 8000 miles. Thanks a million for ANY ideas!!
 
Unplug the fan wire up behind the left scoop and see if one of the connectors inside the black plastic housing has been pushed out or is not making good contact. (ask me how I came to recommend this fix). I have no ideas for the tach.

Sent from my Galaxy Nexus using Tapatalk 4
 
Unplug the fan wire up behind the left scoop and see if one of the connectors inside the black plastic housing has been pushed out or is not making good contact. (ask me how I came to recommend this fix). I have no ideas for the tach.

Sent from my Galaxy Nexus using Tapatalk 4

I believe Dave meant to say the right hand scoop. Probably just a connection issue as he says, but if not, unplug the connector going to the thermo switch (brown and blue wires) and use a jumper wire to join them together. With the ignition on, the fan should run. The bike does not have to be started.
As for the tach, check the connections on the back. Continuity to ground at the black wire, and battery voltage at the brown power wire,(with the ignition on).
Cheers!
 
Well, I didn't really mean scoop at all. It's the wire that goes directly to the fan that runs up over the left front of the motor. One of the pins in my connector had pushed out and was not making contact. Everything looked normal when plugged and unplugged, but during the plugging process one of the pins would move.

Or it's totally something else.
 
When you had the battery area dissassembled to mod the battery box, you may have taken all the ground wires loose on the right hand side of the frame, just outside the battery box area. If you don't get all those ground wires back together and bolted back to the frame, all sorts of weird things can (and do) occur.

In other words: Check all your ground wires. Not just the main one that hooks to the battery.
 
Made some progress today. Got the tach working. No go on the fan. So I unplugged it a the temp sensor. Jumped it with a wire an kicked right on. So I went ahead a wired in a bypass with toggle switch. That will do for now till I try a new sensor. Main thing is seems like I have got the "hot start" problem solved. Only issue now is having a hard time keeping it to idle. Did the pea shooter on the carbs, helped a little. I guess gonna have to pull them an clean them real good. Had to do it once before. So oh well. Gonna tackle that tomorrow. See what happens. Thank you for all the sugestions and help.
 
I think RaWarrior posted-up about using a Nissan Sentra temp sensor, early actuation I believe, and much cheaper than a Yamaha sensor.

http://www.vmaxforum.net/showthread.php?t=19154&highlight=nissan+temperature

And here's a cool mod which may help:
http://www.vmaxforum.net/showthread.php?t=28479&highlight=switch+sensor

A lot of past experiences w/switches, auto and manual:
http://www.vmaxforum.net/showthread.php?t=15320&highlight=switch+sensor

Happy reading! Your answer which best suits you is in-there, somewhere.:punk:
 
Thanks again for all the advice. I really do appreciate it. Well. Pulled the carbs today. Gave them a good cleaning. Borrowed or shall I say rented. LOL. A a set of carb sync gauges from my local independent bike mechanic. Started getting them as balanced as I could. Bike kept wanting to rev up????. It was getting a little hot so I shut it off to take a little break. So I could hear like a air leak or something of that nature. Was coming from the gas cap. HUH?? So I take it off an I swear gas shot out of the tank like a geiser ! EVIDENTLY the vent was plugged an the tank was getting pressurized! That would explain the revving I guess? So ran a small wire in the vent an sprayed w/d 40 an carb cleaner in it. Left the cap off an got the carbs synced. LOL.. Well idles fine now. Gonna look into that vent more tomorrow.. Gonna look into that "sentra" Sensor too. See what they cost. Can't be that much. Once again. Thank you for all the help!!
 
Well. Knock on wood. Looks like I got everything worked out. Everything seems fine now. TOMMOROW may be another story! LOL! Took several test runs. Let the bike sit an idle. Shut off an crank right back up. Run with the fan on an off. So far no problems. Now I can focus on fork seals, Wheel bearings and new tires. Bearings seem fine just gonna change them anyway. Ordered the napa temp sensor. Only like 42.00. So I will give that a try an see how it works out. As deep as i'm in now that's not gonna break me.LOL.. An if at all possible ONLY non ethanol gas if I can help it! Thanks again for all the help!
 
Nice !
You just have to love it when you finally get it running right !!!
 
Just a little update. Got the napa fan sensor switch installed. (An yes you have to use your o-ring. LOL.) Fan kicks on right at the halfway point on the temp guage. As noted in other threads. Before it came on in the red zone. I'm gonna go with this for now an see if it gives me any battery charge issues. Took a few test runs. Not to far. Fan never shut off. So will see what it does on longer rides. With this set up the over ride switch shouldn't be needed. Temp stayed at the halfway mark. At least i'm better off than I was.. So far so good.
 
Just a little update. Got the napa fan sensor switch installed. (An yes you have to use your o-ring. LOL.) Fan kicks on right at the halfway point on the temp guage. As noted in other threads. Before it came on in the red zone. I'm gonna go with this for now an see if it gives me any battery charge issues. Took a few test runs. Not to far. Fan never shut off. So will see what it does on longer rides. With this set up the over ride switch shouldn't be needed. Temp stayed at the halfway mark. At least i'm better off than I was.. So far so good.
I'd hate that since my Bike is always at or just above 1/2 way mark.
So my fan would also be on ALL the time.
I installed the Manual Fan Switch (with the stock temp sensor switch) and I am Very happy with this setup.
 
Took about a 10 mile ride today. Let the fan kick on before I left. Stopped. Checked the fan. Was not on. Headed back home an hit it hard. No problems. Took some little back roads in my little town. Lots of stop signs. Wanted to see if it would kill. All good. Never got past the halfway point on the temp gauge. Checked on getting the fork seals changed. $ 240.00. Not gonna try to do it myself. No help. Not the proper tools. So gonna eat it an have it done.
 
Took about a 10 mile ride today. Let the fan kick on before I left. Stopped. Checked the fan. Was not on. Headed back home an hit it hard. No problems. Took some little back roads in my little town. Lots of stop signs. Wanted to see if it would kill. All good. Never got past the halfway point on the temp gauge. Checked on getting the fork seals changed. $ 240.00. Not gonna try to do it myself. No help. Not the proper tools. So gonna eat it an have it done.

You might as-well install an "All-Balls" set of steering head tapered bearings while you're at it. That will probably make a big difference in your bike's handling, as I bet yours was never adjusted since leaving Japan. They are probably notched and worn. And, have you ever cleaned or greased your front wheel bearings?

You might find someone on here who would help you w/the seal install if you send 'em the fork tubes, or bring them to them if they're close.
 
Fork seals ain't that hard to do.. check morleys youtube channel om how to do it.. I pulled my forks apart and installed progressive springs in about forty minutes. Hardest part was measuring the fluid.

Sent from my SGH-I747M using Tapatalk now Free
 
Just a little update. Got the napa fan sensor switch installed. (An yes you have to use your o-ring. LOL.) Fan kicks on right at the halfway point on the temp guage. As noted in other threads. Before it came on in the red zone. I'm gonna go with this for now an see if it gives me any battery charge issues. Took a few test runs. Not to far. Fan never shut off. So will see what it does on longer rides. With this set up the over ride switch shouldn't be needed. Temp stayed at the halfway mark. At least i'm better off than I was.. So far so good.

Glad to hear. That's how I roll, never had a charging issue with the fan running a lot. And never ran hot again. I like automatic operation. I'd be forgetting to turn the switch off and my fan would be on anyway.
Steve-o
 
You might as-well install an "All-Balls" set of steering head tapered bearings while you're at it. That will probably make a big difference in your bike's handling, as I bet yours was never adjusted since leaving Japan. They are probably notched and worn. And, have you ever cleaned or greased your front wheel bearings?

You might find someone on here who would help you w/the seal install if you send 'em the fork tubes, or bring them to them if they're close.
Your probably right about the steering head bearings. Gonna change the wheel bearings also.
 

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