Electric fans burning out the fuses

[BAsque1]

Originally Posted by Dwight

BAsque1 you said "fans" which I assume is two. Have you checked the amp load of the fans?
Is there a label on the fan or model number where you can see what the fans amp load is suppose to be?

The best way to check is with an amp meter. I bought a industrial 50 amp DC meter and wired it so I can pull a fuse then plug in the meter to read the amp load. Some Multi meter will check a 30 amp load but mine with not. That's way I bought one.

Check a fan last fall that was labeled at 7 amps but when we check it over 15.

Oh, another thing to check is wire size.

Yes I do have 2 13" Bosch fans that came with the car. Last year I changed the fuse holders for each fan because they were deteriorated with age etc. I have to brand new mini fuse holders properly installed. Yesterday I tested the amp draw the second the fans go on at 205 degrees with an induction amp meter. One was 45 amps and the other was close to 100 amps, the one with the 100 amps was closer to the alternator so I attributed the spike to the EMF generated by the nearby alternator. THat been said both fans run freely there is no apparent hesitation or binding that would draw more startup amperage.
I changes the mini-fuses for 30 amp circuit breakers, tested them and they work as they supposed at 205 degrees. However, I will need to use the amp meter that you talk about so that I can accurately test how much start up amperage is being drawn. No the fans only show the model # voltage the amps is 15 according to the manual I have for them. Here is a picture of the info on the fans.

[Gaz64]

And we have found start up current as the cause, as it nearly always is with electric motor faults.

I would swap your fans over, to prove the the fault to a fan motor or EMF from the alternator. I will say the fan motor.

I don't think you have any other "resistances", otherwise they would be glowing with 100 amp spikes, so your wiring is good.

[spdbrake]

Originally Posted by Gaz64

And we have found start up current as the cause, as it nearly always is with electric motor faults.

I would swap your fans over, to prove the the fault to afan motor or EMF from the alternator. I will say the fan motor.

I don't think you have any other "resistances", otherwise they would be glowing with 100 amp spikes, so your wiring is good.

Gaz is correct, https://www.youtube.com/watch?v=gWJFzAMsIlc
and I'd also add pi$$ poor connections add to the excessive Amperage issue. Those are brush fans and as such are life limited on the service life. To isolate each fan I'd connect them one a time to a battery directly. Use an induction clamp on AMP meter. Taking the car out of the equation.
Reading your 1st post this issue started after the fuse holder replacements, so I'd relook at those connections for a the actual number of copper strands in each connection. (Just a few strands=Hi-AMP under load). Many of the cheaper wire strippers nick the copper strands and leave you with just a few actually intact.

[patrickt]

Originally Posted by spdbrake

Reading your 1st post this issue started after the fuse holder replacements, so I'd relook at those connections for a the actual number of copper strands in each connection.

I think that's a tip. Any time a problem has mysteriously appeared right after I did an "improvement" to the car, I know where to look first....

[BAsque1]

Originally Posted by Gaz64

And we have found start up current as the cause, as it nearly always is with electric motor faults.

I would swap your fans over, to prove the the fault toa fan motor or EMF from the alternator. I will say the fan motor.

I don't think you have any other "resistances", otherwise they would be glowing with 100 amp spikes, so your wiring is good.

I am doing a stand alone test with an online ammeter straight to the battery, bypassing the car motor and see what is the kick on amperage and then consider the fan replacement if needed.
This is really annoying now!!

[Michael C Henry]

I've watched the old electric motors with brushes being replaced with brushless motors. The fan in my gas heating stove, then the Dewalt cordless drill drivers. why not electric fan motors on cars? They are more power efficient than the older brushed versions. Why wouldn't the brushless technology eventually be used on electric fans for cars? It may already be available in a better brands, Again I do not know I suppose then there are warehouses' full of the old fan versions, yet to get rid of.

[patrickt]

Originally Posted by Michael C Henry

I've watched electric motor being replaced with brushless motors. The fan in my gas heating stove, then the Dewalt cordless drill drivers. why not electric fan motors on cars? They are more power efficient than the older brushed versions. Why wouldn't the brushless technology eventually be used on electric fans for cars? It may already be available in a better brands, Again I do not know I suppose then there are warehouses' full of the old fan versions, yet to get rid of.

My SPAL puller is brushless, as is almost all of their fans (but not all), but my pushers use brushes.