electric problems with electric fan

[rwhite65]

Ok guys, it is a Taurus fan with a DC controller. The fan just plain quit working tonight. There are no fuses in this set-up, since the custom controller takes care of all that (as I understand).

The fan has been working great this season since install, but now the junk yard piece I think has crapped out. I pulled the harness apart tonight and saw that the ground butt connecters are partially melted. They have black dried/burnt plastic at the connection. Isn't this a sign that the electric motor was going bad, and pulling to much juice? Is there a way to test this motor with an OHM meter?
Unfortunately, electricity is not my strong point. I can say that the fan now makes a clicking noise when I spin it by hand, but does not seem to be loose like it would be if a bearing went bad. I plan on running the hot to the battery directly to eliminate the controller, but am 99% sure already that the controller is fine.

Just to clarify, the ground wires are plenty big, since I used the same gauge the fan used from the factory. The butt connectors I used are also pretty beefy....so I do not really think they are too small to get the job done successfully.
Thanks guys,
Ryan

[~The Jester~]

From what I've heard, that Taurus fan is a pretty healthy unit, pulls like 50 amps, or so I'm told. Sounds to me like the motor is shot. What I would do to test it, is disconnect the fan motor from the controller. Run the wires right to the battery. CAREFUL!!!!! If the motor is shorted/bad it's gonna look like you're welding when you touch the wires to the battery!!!! Just a real quick glancing blow at the postitive while you hold the negative on. If the motor is good, it'll turn over. Now because it's such a high amp motor, it's gonna spark quite a bit even if the fan is good, just cuz it's pulling so much juice. With me so far?

If the fan doesn't move, the fan motor is bad. If the fan starts and runs, the controller and/or wiring is bad.

BE CAREFUL!!! And good luck! Let us know!

[Rev]

I think Jester has hit the nail on the head. That's exactly what I would do to test the fan motor and then go from there.

Rev

[HotRoddin]

Ditto what Jester and Rev said.

If you find the fan to still be good, with the melted insulation you described at the connectors, you might want to check if the crimp is still good at the terminals. When you're working with 12 volts, just a bit of a bad connection between the wire and the terminal (poor crimp?) will give you a little bit of resistance there, and it only takes a very little resistance at 12 volts to drop enough voltage across the connection to create a ton of heat, which makes the connection even worse etc. etc.

Rod

[rwhite65]

Well, the motor appears to still be good. I un-hooked the harness and ran the fan directly off of the battery. Although, I swear the fan sounds a little more "gravely" then it use too, but I guess it could be my imagination.

Not sure if any of you have had a chance to see or deal with the DC Controller, but it really seems like a nice quality unit. I really have my doubts that it went bad, but will have to contact the guy that sells them...see what he says. The controller is a vairable unit...so it may only turn on 20 % of the high output....or 100% depending on the climate conditions and demand the system puts on it.

I thought the fan motor could still work, but be going bad in a way that the fan put more of a load on the system then it was suppose too. There is always the possiblity that the connecter was not a great connnection....I will never know now that the darn thing is basically melted into one.

All other connections are good. The hot and negative to the controller...and the hot and the negative where they leave the controller to go to the fan are all perfectly new looking. Just this one connecter....on the ground wire about 8 inches off the fan's motor melted.

Is there a way to test the electric motor with a multidigital meter? Can someone explain how too do this. I borrowed a meter....but have little knowledge of the things. Would checking the motor for Continuity be something?
thanks guys,
Ryan

[rwhite65]

I am still trying to figure out how to use one of those multi digital meters....but have fixed the fan anyhow.

The general thoughts were that this thing had a lose connection. I replaced the connection...verifying it was good and snug...and have had no probs since. I have checked the wire and it does not feel as though it is getting overly warm. To avoid the lose connections in the future, I am going to use a soldering gun and be done with it.

thanks guys as always,
Ryan

[HotRoddin]

Originally Posted by rwhite65

I am still trying to figure out how to use one of those multi digital meters....but have fixed the fan anyhow.

The general thoughts were that this thing had a lose connection. I replaced the connection...verifying it was good and snug...and have had no probs since. I have checked the wire and it does not feel as though it is getting overly warm. To avoid the lose connections in the future, I am going to use a soldering gun and be done with it.

thanks guys as always,
Ryan

I'd say the solder is a good idea, that is a high current circuit, and the connections HAVE to be really good !!

As far as checking the motor with the meter, you can check continuity, and that might tell you if a winding is open (extremely high resistance), but motor windings normally have almost no resistance, so it will only read 2 or 3 ohms even when everything is good, so unless you're using a good meter and it's reading .0000 ohms, it's gonna be tricky to tell normal motor windings from shorted motor windings.
You should be able to tell if the controller is putting out by measuring voltage right at the motor. If you know the controller should be on, then you can put the meter on DC voltage and you should read close to Battery voltage right at the motor.

Rod

[rwhite65]

nice, now I just got to take a class on how to use one of the multi digital meters...so many choices....
thanks,
Ryan

[Rev]

But the motor and controler combination seem to work OK now? If that's the case, I would just make the solder connections and not worry about it if everything seems to work well.

Rev

[Ieatcamaros]

Don't forget heat shrink tubing. You could just use electrical tape if you wanted to. Most of the time on an automobile, you will be using the DC10v setting, DC50v, and the different ohm settings. TIP* don't have it hooked to the coil while trying to see if its firing. A friend of mine did that and killed his meter.

[rwhite65]

Rev,
The controller and fan are working very well now. I have been keeping an eye on it here, but am to the point that I am going to solder them up and forget about em.

Ieatcamaros,
I will definately use heat shrink vs the electircal tape. Something about this car having the hood up and people seeing electrical tape in my system...just doesn't set well with me. Granted the electrical tap has its place on plenty of my toys, just not on this car.

[tmoss]

soldering high current connections is always a mandatory step for long term reliability. Heat shrink over them after makes for a very professional finished product - forget tape.