Um.. thats not a front to back veiw... thats top to bottom of the fins. The air flows through the 'v's

 

LOL!! My bad, it was only the radiator fan blade that I bought, the clutch is extra. To me both fans look the same but everyone I had spoken to tells me they are different.

 

the vicious fan is not electric... he is talking about the electric secondary fan.

 

The fins look fine. Condensers are pretty restrictive anyway, but they allow just enough airflow.

To pop a 40A fuse means you have a direct short or the fan is sucking waaaay too much.

It's an issue on the power side, so use your DVOM to check:

1. Resistance of the wire from the 40A fuse to the relays (there are 2). There should be no more than a few (2-5) Ohms.
2. Resistance of the wire from the relays to the fan. There should be no more than a few Ohms.
3. Resistance of any of those wires to the body (ground). There should be a significant amount of resistance (K Ohms or M Ohms). Any measurable continuity may be an issue as these are on the power side.
4. Resistance of the relays on the power side. The relays will have to be switched CLOSED via the power side using a 12V source. There should be no more than a few Ohms. Switched OPEN, there should be no measurable continuity on the power side of the relay.
5. Check the resistance of the fan itself. There should be no more than 5-10 Ohms if I recall correctly. If it's significantly higher or lower, your fan motor might be shot (the best is to compare it to a known working fan). This number could pin point the issue to your fan.

 

Wow, such good advice. I'll definitely check those and let you guys know the outcome. Thanks.

 

I know it's been a very long time, but I finally just got around to performing these tests. Unfortunately everything checked out fine. I double, and even triple checked everything. There was continuity where there was supposed to be continuity and there wasn't any where there shouldn't have been any. I'm stumped and open to any more suggestions on what to check next.

 

From the beginning of the post: Its a bad fan.

 

When powered directly, the fan works just fine. That, and there was no resistance in the fan when I checked it with a multimeter.

 

Absolutely no resistance? As in 0 ohms? If so, the fan motor could be shorted, which would cause a high draw and pop the fuse. Conclusion? Bad fan. The fan motor should have some resistance, maybe 2-5 ohms if I had to guess.

 

Correct, the fan has no resistance at all. It does work when wired directly to a 12v source, it just squeaks a tiny bit. So it's unlikely to be anything else? If that's the case, then I guess I'll go get a new one.