Radiator fan problem

[bob_menton]

Normally on my '02 LT (and on the previous LT, a '99) when the radiator temp rose to near the top of the scale (stop-and-go riding), the fans would come on, run until the temp dropped to just above the 1/2 way tick mark, and then shut off. This cycle would then repeat if I was still in stop-and-go traffic.

Now in stop-and-go traffic the temp rises, the fans both come on, and run for only 10 seconds, then shut off. Mebbe 30 seconds later the fans will turn on again, run for mebbe 30 seconds this time, and shut off. In neither case does the temp drop to anywhere near the 1/2 way tick mark - it drops a little bit when the fans run for 30 seconds, but not much.

Anyone else ever see this? Under extended Pinnacle warranty - going into the dealer next week for diagnosis and (hopefully) repair. I'll let y'all know what happens then.

- Bob

[ibbones]

Normally on my '02 LT (and on the previous LT, a '99) when the radiator temp rose to near the top of the scale (stop-and-go riding), the fans would come on, run until the temp dropped to just above the 1/2 way tick mark, and then shut off. This cycle would then repeat if I was still in stop-and-go traffic. Bob

I have an 02 and mine come on like yours also. Drops to about the half way mark and then cuts off. I have not experienced the on/off thing.

[bob_menton]

Well, I got the bike back from the dealer today. It wouldn't misbehave while the dealer checked it out. Fans turned on at 221 deg. F coolant temp, turned off at 210 deg. F, back on at 221 deg. F, etc .....

Prior to this past spring, when I let the bike idle in my driveway until both fans turned on (and noticed how quickly they turned off), my cooling fans may not have operated for years. As you probably know, as long as you're moving, flow of air thru the radiators is sufficient to control coolant temp without the fans running. My kind of riding is such that I rarely get in stop-and-go traffic.

Sooooo ........... from now on, I shall occasionally let the bike idle in the driveway and cycle the cooling fan function. "Use it or lose it" may be the cure for this problem.

- Bob

[mneblett]

Now in stop-and-go traffic the temp rises, the fans both come on, and run for only 10 seconds, then shut off. Mebbe 30 seconds later the fans will turn on again, run for mebbe 30 seconds this time, and shut off. In neither case does the temp drop to anywhere near the 1/2 way tick mark - it drops a little bit when the fans run for 30 seconds, but not much.Bob, did your dealer take the bike out on the road, or just let it sit and idle up to fan temp? I'm wondering whether the problem is a flakey/failing fan relay -- if the coil is barely holding the contacts closed, road vibration could be sufficient to cause the contacts to open -- something that wouldn't be detected sitting in a service bay. Although its a pita to get to the under-tank electrical box, you might want to exchange the relay with one of the others in the box to see whether the problem clears. (Of course, all the above assumes you've already checked that the problem isn't a physical problem with the wires that control the relay).