68ragtopLS1

I'm running a Flex-a-lite black magic fan with a painless relay. I'm using a Speartech harness. The problem is that I was having overheating problems when stuck in a traffic jam and found out my fan was not working. I read in previous posts how Speartech said how to test the relay and the fan. I found out my relay was bad and the fan motor was bad. I replaced both of them and it worked great for maybe a week. Now they are both burned out again.(I tried testing the fan by wiring it right to the battery). I'm sure my wiring connections are right as Speartech walked me through them last year when I installed everything. Does anybody have any idea what could be causing this? Thanks, John

jeromio

Perhaps your fan blade(s) are f'd up. What did the bad motor look like? Melty?

68ragtopLS1

No. I could not tell anything was wrong with it except when wiring it straight to the battery it would not do anything. It was still under warrenty so I got it replaced for free. When I got the new one I hooked it to the battery and it worked good. Then I put it in the car and it did not work so I started testing the relay. I replaced the relay and it worked great. Now I'm right back at the same place again. Something is causing these to go bad. I just can't figure out what. John

Speartech

iTrader: (14)

I can't think of any way to improperly wire up the fan that would actually make it go bad or "burn up".

If you wire it backwards, it will run backwards; if you have a poor connection, it will run slower; if you have a bad connection it won't run at all. Nothing there would really damage the fan motor.

Could it be rubbing on something when it's installed on the car? If it were rubbing on something when it comes on, that would make it draw more current, which could burn it up.

gEtyOPaPiOn

iTrader: (11)

the only thing i can think about its the fan polarity being reversed while running somehow with the relay(kinda like 99.9%) imposible lol but if you try to draw a diagram of a misswiring like this i just cant come up with it ...so i can only think ...cheap motors/cheap relays

Speed Scene Wiring

One way that can happen, is if the fan windings short directly to ground, when the relay is engaged by computer PWM control. Once again the problem is most likely in the fan motor. You can also test the resistance on the relay coils. 85 and 86. The resistance in most Bosch relays will be 85.3 OHMS. If your reading is infinite you have a blown resistor bridge. Get a new relay. Try a new fan with a Speed Scene Wiring fan kit.

DaleMX

iTrader: (4)

There was a post over on www.hybridz.org about this very problem. Fans should be wired with a diode placed across the leads to prevent back spinning causing a current surge and arcing on the relay. Also the fan power lead should alway be run from the alternator connection and not the battery. I'll go look for the link and post if for your reading enjoyment.

DaleMX

iTrader: (4)

Ok, here ya go. The stuff you want is on the second page.

http://forums.hybridz.org/showthread.php?t=103129

DaleMX

iTrader: (4)

Oh yea, and here is another example of a diode protected setup.

http://www.fordmuscle.com/archives/2...an/index.shtml