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Sniper EFI is controlling the relays to the fans ..Alternator comes with the Holley mid-mount system .. Don't think the fans are noisy at all ..Fans are made in Taiwan how long are they going to last ? will c...Bought these on the cheap and they fit really good ..
Mahalos...
I'm in the process of an engine swap and got a 140amp alt. I'm doing some other things and wanted to alt to keep up. Thanks for the sensor info. Got a part # ?
I have the sensor, pigtail and adapter if interested. Shoot me a PM.
BMW Dual temp sensor #61318361787. Rock Auto has it. Youll need the pig tail connector/ 3 wire also but I cant find that #.Also youll need a metric to sae adaptor to fit your location
Where did you find the bits to make that connector? I have that sensor, but short of getting a connector at a junkyard, making up the connection seems to be a lot of hunting down parts.
Where did you find the bits to make that connector? I have that sensor, but short of getting a connector at a junkyard, making up the connection seems to be a lot of hunting down parts.
You can get it thru BMW although Id try to source it elsewhere. Its been awhile since I did mine and I cant remember where I got it.
Wouldnt the original C5 sensor and pig tail work? Then just wire it to 2 relays?
You can absolutely do that, too. That's basically what I have in my car, dual relays, dual fuses, dual wiring, but still the single point failure of the single temp sensor. Having a dual-range switch (like the BMW switch), or even two switches means that the fans come on at different times, so you get reduced current spikes, load-dependent sequential fans, and free redundancy. You can do all that even better with a PWM fan controller with an actual temperature sensor, but I like the simplicity of switches and relays for something I need to rely on.
I figure you're discussing these fuse-holders? Can you elaborate on what is wrong with them? I'm just wanting to learn because I have a similar fuse holder on my fan control circuit (mine only handles the control circuit amps so not the same thing). What is "rolled" part that you mention?
You can't see the rolled sides of the fuse terminals, that are shaped like U's? That type is junk for higher current loads. It simply doesn't clamp well enough, then starts dropping voltage and heating up until the connection burns. Look at a Packard 54 terminal, that's what you want to clip onto a Bosch style relay. I would use a fusible link for the power, not a fuse.
Originally Posted by 0311 jarhead
Wouldnt the original C5 sensor and pig tail work? Then just wire it to 2 relays?
C5 uses the PCM to control the fans and has 3 relays, not 2. Hi-low speed control uses 3 relays.
Last edited by lionelhutz; Aug 22, 2021 at 09:55 PM.
i ran the fans off a small battery charger and they showed 8 amps each. quick spike to 10 amps when starting. OE stuff may be better engineered and draw less power. i have 2 alternators for and in my 01 gmc box truck. i may use one in my 75 after homeworking brackets.
Thank you for your question. The Dorman electric fan 620-634 has an 1,150 cfm rating per fan.
I had mounted a 16in 2400 cfm fan in the orignal fan shroud that was supposed to work but it didn't keep the temps down ,at idle it would just keep rising .These dual fans in high speed work good to keep the temps down. ,..
Thank you for your question. The Dorman electric fan 620-634 has an 1,150 cfm rating per fan.
I had mounted a 16in 2400 cfm fan in the orignal fan shroud that was supposed to work but it didn't keep the temps down ,at idle it would just keep rising .These dual fans in high speed work good to keep the temps down. ,..
I'm a little confused. You have 2 speeds on the fans? You run 1 fan at a time? or do both fans run together at the same speed?
Still wondering about how much air they move compared to other fans. Telling me they are replacement C5 fans certainly doesn't answer that question.
i don't have an answer for how many CFM, but chevy engineers had an additional 20 years to figure out how much air a fairly high HP small block needs to stay cool in a 2 seat sports car with a crazy person stepping on the gas. now, hawaii guy's silverado, fans are probably fine, but size and shape of radiator may dictate a bigger dia single fan for a squarer radiator cross section. my 4.0 grand cherokee had no cooling problems except then the fan motor died. which is in itself an argument for dual fans.
Last edited by derekderek; Aug 24, 2021 at 07:43 AM.
Old wires, sensor adaptor needed etc... Sure you can buy 'new' wires from BMW but they're the same color and need to be spliced. Ron Francis kit, one sensor, no adaptor. One wire from sensor to relays.
Here’s a simple diagram how my fans are wired.Sniper ECU controls the high and low Relays . You can use a temp switch or controller in its place .. I’m using two relays a SPST for low speed and a DPDT for high speed . You could use two SPST relays in place of the DPDT relay it’s up to you .. Mahalos !
