John OoSTerhuis
Life Is Good!
+1
Is the fan kicking on?
I may have missed it, but how did your coolant hoses look when you pulled the carbs? Are they the original 24 y/o parts?
John
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blown head gasket
- Thread starter raybonz
- Start date
Is the fan kicking on?
I may have missed it, but how did your coolant hoses look when you pulled the carbs? Are they the original 24 y/o parts?
John
Yeah John, the fan is kicking on and the hoses looked almost new. After I replaced the t-stat yesterday ( 39 bucks for a thermostat!! ) I started for work and everything was looking good until I came to a stop sign. After that the gauge slowly increased until it was just below the red mark. That was 14 miles from home. After turning around, there was a slight grade to go up but the temp never went higher but neither did it go down the rest of the way home. When I pulled in the garage and turned it off, I heard the fan running so I know that's working. After looking at both the Honda service manual and the Clymer, I'm no closer to a fix than before. The thought of repair by replacing until you get the right thing makes me crazy!
John OoSTerhuis
Life Is Good!
Double-check the coolant level at the radiator cap. Fan should kick in around the time the needle in the gage is vertical (12 o'clock). Thermostat installed correctly? The odds of a faulty (stuck closed) new thermo are pretty low, but...
Did this just start since you changed the head gasket, or was this present before that? How long have you owned the bike and what do you know about its maintenance history?
Your symptoms are starting to sound a lot like what I had a year ago, but even a little worse. I brain farted and let my coolant go something like 8 years, maybe 10, without changing it. I somehow totally forgot about it. During that time the steel impeller blades on my water pump had rusted such that the 90-degree blades that move the water were gone. So picture a fan with totally flat blades, that's what I had left. Funny thing is it still seemed to work OK for years, the only symptom was when I'd stop at lights on hot days the gauge would get up to 12-1 o'clock pretty quickly and then take a while to come back down. While running at speed it would mostly run normal temp, then occasionally the gauge would go up rapidly to 12-1 o'clock and then come back down almost as rapidly. I thought it was the gauge acting up, but replaced the t-stat anyway, and it didn't really help much but seemed a little bit better. Finally replaced the water pump and that fixed the problem.
Your symptoms are starting to sound a lot like what I had a year ago, but even a little worse. I brain farted and let my coolant go something like 8 years, maybe 10, without changing it. I somehow totally forgot about it. During that time the steel impeller blades on my water pump had rusted such that the 90-degree blades that move the water were gone. So picture a fan with totally flat blades, that's what I had left. Funny thing is it still seemed to work OK for years, the only symptom was when I'd stop at lights on hot days the gauge would get up to 12-1 o'clock pretty quickly and then take a while to come back down. While running at speed it would mostly run normal temp, then occasionally the gauge would go up rapidly to 12-1 o'clock and then come back down almost as rapidly. I thought it was the gauge acting up, but replaced the t-stat anyway, and it didn't really help much but seemed a little bit better. Finally replaced the water pump and that fixed the problem.
In answer to your question, yes, it started after I changed the head gasket. Before that no cooling system issues. I bought the bike in 2010 with 52,000 miles and the guy I got it from was pretty good about maintenance. He gave me a small folder of everything he had ever done but except for coolant change, no mention of any issues with the system. I checked to see that I had put the t-stat in correctly this morning and with it running and the cap off, looked in the filler neck. A good flow of coolant was coming out so I hope that's an indication that the water pump is ok. With the bike off, the coolant level is at the bottom of the filler neck. I took the cap and had it checked and was only holding 10psi. Supposed to be 18-20 so looks like that will be the next item to be replaced.
Ok, update time. After riding 5 miles 2 days in a row, I find the fan is not coming on at all. So I attached the battery leads to the fan and nothing. Then I took the radiator out and checked it on the bench and again, nothing. But it did work the first time I took her out after I replaced the head gasket and re-routed the crankcase vent. Hmmm. So after checking Ebay I was shocked to see the cost of a new one. Looks like used for me.
If you're riding at speeds of 45+ continually the temp gauge should remain quite low from the airflow across the radiator regardless of the fan condition, so if your gauge is mid-range under those conditions then there's something else to address as well. If you were stopping frequently then that's a different story, gauge creep should be expected then.
that's weird, what lousy luck. Did you check the wiring all the way to the actual motor contacts to verify you don't just have a minor wire failure?
+1 on that, if it worked once I'd start checking power and ground.
He mentioned earlier that he'd bench tested it and it was still dead. What I was referring to is make sure there's no open circuit between the fan power connector and the actual motor winding itself. Not sure how much access is available to verify that, but a close visual inspection might reveal something simple. On something that has such a low duty cycle it would be bad luck to have the actual motor go out.
I missed that it had already been bench tested.
My bad.
My bad.
Yeah dwalby, from the fuse block thru the wire loom and the connecter, everything else is fine. I think it's just a case of being 23 years old and things are wearing out, Just seems they're all going at once though. Speed wise, I rode from 30-70mph to get a good range reading. Though it has been quite warm here(95-100), that's normal temps and what I've been riding in all the time. So far I've changed the t-stat, radiator cap and coolant. Except for the thermo switch and radiator there isn't much left.
The part I'm asking about is the wiring on the other side of the connector to the fan itself. Have you looked at it to see if there's some kind of open circuit between the fan connector plug, and the fan motor itself? For example, maybe the wire going into the connector has slipped loose, so even if you apply 12V directly to the connector pin, it has no way of getting to the motor winding because the circuit is broken.
Anybody mentioned this yet? . . . . In the first couple of years of ST1100 production, the fan bolts were coming loose because Honda had not put thread locker on the threads. Has the fan come off its bolts?
John OoSTerhuis
Life Is Good!
The manual does call for thread locker on the nut holding the fan to the motor shaft, but be very careful not get any on the plastic!
John
John
OK, sorry it's taken so long to reply but now that the new fan is here, I'll update. As I said before, I hooked up the battery directly to the old fan and nothing. So today the new fan got here and still nothing. It's from an 03 but all connections are the same. What am I doing wrong?! Are there not only 2 wires to the stupid thing! I even hooked the ground onto the frame and that didn't work. The Honda shop manual I bought is useless except for illustrations and the Clymer gives the procedure after it's out of the bike which is what I've done but still nothing. Hard to believe I got a bad motor to replace my bad one, but anything is possible.
keep in mind you need to flow a reasonable amount of current to get the fan to turn. If you're just poking at the terminals with 12v you have to make a secure enough connection to flow adequate current or it won't work.
edit: when you say the new fan is not working, are you still bench testing, or did you plug it into the bike connectors? Make sure the green wire has continuity to ground and isn't corroded and not making a good ground. then if you have 12v on the other wire, that should do it.
edit: when you say the new fan is not working, are you still bench testing, or did you plug it into the bike connectors? Make sure the green wire has continuity to ground and isn't corroded and not making a good ground. then if you have 12v on the other wire, that should do it.
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ST1100Y
Site Supporter
Should have a black/blue wire (positive) and a green wire (ground), later ends in a crimp bolted to the motor bracket; and then there is a line (IIRC black) going from the motor to the fan/stat which is the actual ground for the motor; so attach + to the black/blue and - to that "loose" wire supposed to be plugged on the Klixon in the radiator... if I remember that all correctly...
Finally some good news to report! My old fan was in fact good, I was testing wrong. After connecting correctly(thanks ST1100Y!), it worked perfectly. I checked the thermo switch and that was the problem. Got a new one,put everything back together and viola! Test ride went great with the fan coming on and she cooled right down. So all is right in my world-sort of. Now the low beams won't come on but the high beams do. I can make that work but have any of you had this problem before? The fuse is good and the switch seems ok-relay maybe? I have a low and high beam relay. Any way to check them? Thanks.
ST1100Y
Site Supporter
So one issue fixed, one more to go... ;-)
Since your ST is a US model with hard wired low beams, I suspect:
- an issue with the starter button, rather with the contacts behind it: one closes (starter solenoid) whilst the other opens the feed to the low beam relay, to reduce the load on the system while cranking
- an issue with the contacts of the HIGH/LOW switch
Depending on age, conditions and storage/parking of the bike, those switch-sets can get prone to collecting dirt and/or corrosion.
Take them apart (not completely, only spilt the cases so far to get access for the spray nozzle, and place a rag underneath to not mess up paint and other body-panels), and threat them with dielectric contact cleaner/lubricant (see to get one rated to be safe on plastics); put them back together (note the stub that has to go into a bore in the handlebar, preventing the housings from rotating/slipping), should work then...
There could be other causes, like corroded connections, faulty LOW beam relay, corroded fuse box, broken wire, etc... but switches seem most likely and easy to fix.
hope this helps
Contacts in rocker switch corroded.......remove and clean.....reassemble.......DAHIK ...