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I installed a volvo dual speed fan today along with the relays and BMW temp sensor. had no room to install on the inside so i installed it as a puller. its super loud. Had my truck idling for about 25 min. and both speeds kicked in. .. just need to clean it up. with the fan running high my battery was at 13.94. the bracket around the fan i took from a volvo as well.















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Looks like on the outside of the radiator so wouldn't that push air through it. Hopefully we are meaning the same thing but we have had electric fans blowing air forward into the direction of travel before.


You have it fused and 'on' all the time? Mine will sometimes come on after I get out and start walking away and this reduces any heat spike and makes restarts easier.

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Factory electric fans are engineered as pullers and are mounted behind the rad. The shrouding around the fan helps control air flow. The fan blades then are shaped or "scalloped" to maximize pulling efficiency while reducing noise, so simply reversing the fan motor direction won't create the same amount of CFM. The "reversible" aftermarket electric fans are far more basic shape to the fan blades, the trade-off to run in either direction.


Here's how I did my puller-to-pusher conversion:

1st step was to confirm operation and noise of my salvage yard fan. I bought a few candidates to choose from.

Had a winner so time to make it blow! Note the rotation direction of the blades.


The fan was disassembled and then I very carefully cut the hub off from the ring the blades projected from. You want to be sure that cut is parallel all the way around.

A few test fits and I was able to use the moulding ribs to help "lock" the inner hub to the outer ring.

I made up a support to help keep the parts parallel and aligned while the epoxy set.


Overall balance is important too. I balanced the modified blade assembly and confirmed there was no run-out or wobble as it turned.

Next test was to spin it by the motor and again check for wobble or run-out, and that the assembly wouldn't grenade.

Final reassembly. Note the arrow on the fan blade showing the rotational direction the fan needs to turn is retained.


Since a pusher fan by default blocks some of the air flow into the rad, I chose to keep as much of the cooling fins unobstructed as possible. I can add shrouding later if needed.

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iNTERESTING, When we built our race cars and had an aluminum radiator fitted we completely isolated the radiator with non-conductive washers and sheathed the bolts holding it in place to prevent any electrolysis.  It seemed to occur only if the aluminum  was in contact with steel.  The aluminum degrades as the sacrificial metal.

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On 11/6/2022 at 11:07 PM, datzenmike said:

If it was turning the direction of the arrow it would be pushing air into the radiator not pulling it

If you look again, the direction of the arrow would be pulling air... from the engine side of the radiator

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8 hours ago, datzenmike said:



If this was on the engine side of the radiator and the fan turning as indicated, it would be pushing air into the rad. (beginning to think we may be looking at it differently and are both right. Carry on.



In this pic the rad would be between the pic and your face, so the fan would be pulling air through the rad away from your face


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