Question re: 4107 Driver/Defroster Fan (Over Windshield)

[Runcutter]

Last weekend, I reinstalled the original driver fan - mounted over the windshield.  Got a new Baader Brown motor from a schoolbus parts supplier on the web.  The only apparent difference is that new motor is dual speed, not single speed.  I'd also purchased a second fan, so one could blow on me, and one on the right front passenger seat.  My surprise, when I wired them up, was that only one could run at a time - connecting both to the original wiring (temporary butt connector) caused both to stop - apparently not enough amperage?  The motors are dual speed, and I connected both using the higher speed (we are in Texas, after all).  Wiring is original, from the driver fan switch on the dashboard.

I'm out of town for the next two weeks, so don't have access to the wiring diagrams or the coach.  I don't know if there's a relay between the fan switch and the fan motor.  My thinking is that the motors draw more amperage than the wire can support - but it seems strange to me that GM played it that close on a small electrical device.

If I can rewire with heavier gauge (if so, any suggestions for the best gauge), is it likely that the wire runs from the destination sign box to the left pillar, down past the gasper, and connects to the dash switch? - and is it possible to fish a new wire through there? 

Any thoughts?  ---  And thanks in advance.

Arthur

[Dallas]

Arthur,

I'd almost bet you dollars to donuts that your dash has very little or no ground.

Try using a jumper wire from the ground at the breaker panel directly to the fan motor.

The other possibility is the fans are wired opposite each other.... one is set up as negative hot and the other is positive hot. It shouldn't make a difference, but I had 2 fresh air intake blowers on my 4103 that were wired that way. when I set them up to use as blowers for moving air around the bus, they would stop. Both were 2 speed 12V fans with the same color wiring. The difference was on the model number.... one ended in R and one ended in L

I hope that helps.

Dallas

[Runcutter]

Dallas, thanks.  The ground issue makes sense - and I hadn't thought of that.  Both motors are identical, same model purchased/shipped simultaneously from the schoolbus parts supplier.  Ground is through the motor/mounting bracket - that may be the weak spot.  I'll try making sure they each have a good ground; and I'll connect them one at a time to be sure they turn in the same direction.  Unfortunately, I don't fly home until the end of the month, so I can't check it out until then.  On the other hand, if I'm in New York state, and the bus is in Texas, there's no harm in the delay.

Thanks.

Arthur

[Busted Knuckle]

[quote author]
Dallas, thanks.  The ground issue makes sense - and I hadn't thought of that.    On the other hand, if I'm in New York state, and the bus is in Texas, there's no harm in the delay.

Thanks.

Arthur[/quote]

Art do you realize what you just said? I'll translate! "If the bus is in DIXIE,and I'm in SIBERIA theres no harm in the delay!"  Ahh buddy have ya had yer blood sugar/pressure checked, have ya switched or missed taking any of yer meds, did ya bump yer head, are ya feeling dizzy, is everything in fast motion?!?!?
If you answered yes to any of these questions, by all means. For your own good go to the nearest airport and get the very first direct flight outta there! Go straight to the bus, give it a big warm hug, and a sloppy kiss! And tell it your sorry you'll never leave it alone like that again!
  BK 

[Runcutter]

Bryce, i get your point.  However, the reason I'm in New York is to earn money to pay for her tires, maybe some airbags, etc.  Since I'm in New York the nonworking fans in the bus in Texas won't cause any sweat stains.  Now, by the time I get home on July 30, the Texas heat will make the fans priority one - thus this question. 

It's become interesting that I now evaluate projects and contracts by what they'll buy for the bus (ooh, ooh, a scheduling review should be just about right for power steering).  I've worked in the bus business for almost four decades .... but never thought I'd be working to support a bus.

Now, as to the meds ...  which ones --  those from the urologist, the hernia surgeon, or the nice guy that did my colonoscopy last week?

Arthur