Volvo V70 fan blowing fuses

[icetherice]

This might be in the wrong section but I didn't see a section dedicated to cooling so I figured I'd post here.

I hacked in a fan from a V70 today and wired it accordingly with a 30 amp relay to a switch.

Every time I try to hit the fan it smokes the fuse.

Is this fan too much for a 30 amp circuit?

 

[RonD]

You need to use a Maxi or SloBlow 40amp fuse or 30/40amp fusible Link

Any electric motor will have a voltage spike on startup, this fan should draw about 15-20amps AFTER it is started, if its working OK
Volvo didn't use a fuse just the relay to battery directly

 

[icetherice]

Thanks Ron, I forgot about inrush current. I'm currently running an ATG fuse so that makes sense. Do you think my 30 amp relay going to survive the initial surge of current..or do I need to source something beefier.

 

[RonD]

As far as I know Volvo used a 40amp relay, but 30amp should be OK

Read a post that said Volvo fan can spike as high a 65amps on startup then settle in at 25amp

The newer Volvo fan relays are not too expensive and have heat sinks: https://www.ebay.com/itm/New-Coolin...0-V70-XC70-XC60-/352273329341?fits=Make:Volvo

 

[icetherice]

Wow really... I have the fan that had the PWM control module attached to it. I cut that off and wired it direct. I just picked up an 8awg blade-type maxi fuse holder, a 30 and 40 amp maxi fuse, and a 40 amp relay.

 

[RonD]

Yes, but you are building it for yourself

Car makers have to build it for long term and harsh climates, and then the engineer that designs a part has to explain, just before being fired, on why their relay(or PWM) is now being recalled on all models and engines are being burned up because of electric fan failure, lol.

"hey it works" is not practical in mass production

 

[icetherice]

Very true. Maxi fuse did the trick, 30amp relay hasn't welded itself shut yet, gonna keep the 40amp on hand though.

Pics included.

Bonus picture of my catch can setup, works pretty well, started catching fluid the first day.

 

[RonD]

Very nice setup

Yes, catch cans condense the oil out of the air coming out of crankcase.

Blowby vaporizes some of the oil on cylinder walls and piston sides every time a cylinder fires, unavoidable for piston engines
When engine gets more miles then there is more blowby so more oil vapor

PCV Valve(system) is there to suck out the Blowby gases(exhaust gases) and reburn them in the engine.
As the oil vapor percentage gets higher it gets up to the valve cover area and it is also sucked into PCV valve and into the intake, not a good thing for efficiency and general running conditions
Adding a catch can gives the oil vapor cooler surfaces to condense on so less makes it into the intake, especially where you placed it, away from the heat of the engine

 

[icetherice]

Well she's only got about 12,000 miles on her so I hope blowby isn't too bad yet haha Did a compression test last week with 150 across the board.

Thanks again for your prompt responses, Ron