Question for the Experts: E40 Electronic Fan Clutch

I have a very unusual project. I won?t bore you with the details, but it is an E40 ECM running a non-LS engine.

I have two potential problems. The first is that I am using a non-electronically controlled transmission. I understand that the SSR tune can be set up to run a manual transmission or in my case and non-electronic automatic transmission.

The second problem I have is that I was planning to use the electronic fan clutch from the Chevy Trailblazer.

I have the wiring diagrams for both vehicles. The issue I think I may have is that if I use a base tune from the SSR, it will not be set up to use the trailblazer type fan clutch. If I use the trailblazer tune, it will be set up for an automatic transmission. I know that HP tuners will allow me to select an electronic fan clutch as an option, so I?m wondering if I can use a base tune for the SSR, and then just change the type of fan in the software and then wire it like the trailblazer. I?m kind of stumped here and I really don?t want to go to electric fans if I can help it.

Any advice would be appreciated .

E40 is technically a Gen3, or Gen 3-1/2, but 'round these parts E40 stuff goes in the Gen4 section.

I think you'll be mighty disappointed with the electro-viscous clutch. They are fail-prone, veeeery slow to respond to commanded duty cycle, and because of the way the fluid settles when the engine is shut off during most (but not all!) cold starts the fan stays stuck at 100% for 3-4 minutes until the fluid gets redistributed where it should be. Generally an all-around giant pain in the ass.

But yes, the SSR uses the same base OS (12612557) as the TB/Envoy that use the EV fan. Just change the fan settings and go. Just make sure you can live with the misbehavior before you invest a lot of time and effort.

Thanks. This is for a big big big RV radiator and I like the idea of having the massive cfm flow of the mechanical fan when needed. Also, I could use the extra amps from the alternator to charge house batteries vs driving electric fans.

I’ll repost this in the Gen IV section. Thanks again.

Oh, I like the idea of the EV fan too, it's just the way it should work in theory doesn't match up with reality.

You should look at the 19" brushless fan from CTS-V/Camaro SS. Speed controller is built in, just requires constant hot/ground and a single PWM wire (the same pin as what controls the EV fan).

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Originally Posted by blindsquirrel

Oh, I like the idea of the EV fan too, it's just the way it should work in theory doesn't match up with reality.

You should look at the 19" brushless fan from CTS-V/Camaro SS. Speed controller is built in, just requires constant hot/ground and a single PWM wire (the same pin as what controls the EV fan).

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OK. You convinced me. I did some more research and found that even GM dumped the EV fan clutch from the Trailblazer in 08-09. Now I have to decide between old school thermal fan clutch and the Camaro Fan. That thing does seem to move some air. The only question I have is if I flash the ECM as a M6 SSR, and then change the fan settings for a PWM single fan; will it be OK to not have some of the normal inputs? I guess on the Trailblazer, one of the parameters for fan speed is Transmission temp, which I won't have since mine will be flashed as a manual trans.

If this won't work I'll either just do a thermal clutch, or use dual electrics and wire it like the SSR is from the factory except with two fans. This tuning thing is new for me. I've done an LS swapped BMW, but I farmed the programming out because it was much simpler setup than this is.

It doesn't use trans temp for any of the fan tables, only ECT & AC high-side pressure, and those are independent - it uses the higher of the two at whatever point in time. So, if there's no AC sensor input, it only uses the ECT like normal. Nothing else is affected.

Please don't mess with discrete fans especially if one of your priorities is current draw. An infinitely variable speed fan can run at just 8-10 amps if that's all that is needed, a on-off fan is all or nothing (or, the stock SSR/GTO setup with 2 fans in series for low and both fans in parallel for high only gives you 0%/50%/100%, and 50% is way more than 10A).

The SPAL brushless fans are just amazing. Soft-start, no dimming lights, no melted wires or relay sockets.

For some reason I haven't been able to figure out, an E40 can't use the same settings for the SPAL fan as the E38/E92 in the CTS-V/Camaro. Use PWM Electric/128hz and it works like a charm. I can get you part numbers for the special Yazaki connector and related bits if you need that.

Quote:

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Originally Posted by blindsquirrel

It doesn't use trans temp for any of the fan tables, only ECT & AC high-side pressure, and those are independent - it uses the higher of the two at whatever point in time. So, if there's no AC sensor input, it only uses the ECT like normal. Nothing else is affected.

Please don't mess with discrete fans especially if one of your priorities is current draw. An infinitely variable speed fan can run at just 8-10 amps if that's all that is needed, a on-off fan is all or nothing (or, the stock SSR/GTO setup with 2 fans in series for low and both fans in parallel for high only gives you 0%/50%/100%, and 50% is way more than 10A).

The SPAL brushless fans are just amazing. Soft-start, no dimming lights, no melted wires or relay sockets.

For some reason I haven't been able to figure out, an E40 can't use the same settings for the SPAL fan as the E38/E92 in the CTS-V/Camaro. Use PWM Electric/128hz and it works like a charm. I can get you part numbers for the special Yazaki connector and related bits if you need that.

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I just pulled the trigger on the fan assembly. Under $300 shipped isn't bad for that monster. I'll have to adapt the fan shroud to my larger radiator, but that won't be too hard.

Can I get the part numbers for the electrical connector and any other important bits? Thanks again.

On a somewhat related note.....I assume that you tune professionally. Where are you located?

Ha! Hardly. I just have experience with replacing hundreds of failed EV clutches on Trailblazers in my former life as a dealership tech, and I currently own an '06 Envoy with the 14" C7 Vette SPAL fan (hindsight, I really should have gone with the CTS-V fan, it would have been less work and about the same money). I just know this one platform rather intimately. And I couldn't find anyone else who'd tried the SPAL/E40 combo so I slogged through it myself and just made it work.

Use this for the fan harness connector: https://www.ebay.com/itm/233178180273
Being that you're doing everything custom and not trying to adapt to an existing OEM harness I don't think you will need anything else special.

At "850 watts" the napkin-math max current draw will be 60A @ 14v, and 80A @ 12v (but, if you ever try running the fan at 100% with the engine off, you got bigger problems...). Use 8AWG wire. Conveniently that uncrimped connector will accept up to 8AWG. Crimp and solder, don't rely on just one or the other. Solder prevents the crimp from loosening with time/vibration, and the crimp prevents the wire from falling out if something goes wrong and it ever gets hot enough to melt the solder. Belt and braces. It should be OK with an 80A fuse, personally I would use 100A.

As a point of reference the little baby 14" fan in my truck has never needed to run at more than 55%, and I have the ECT & AC tables set to request much more fan than the stock tune did.

https://i.imgur.com/ulvRQgG.jpg

In your table(s), 0%-14% is OFF, 15% it runs at minimum. 90% is full speed.

Dunno if you've got diagrams for one of the cars that came with the SPAL fan or not, but there's no relay needed at all like the Trailblazer had. Just straight from C1 pin 36 right to the signal wire at the fan. Fan motor has an internal pullup resistor and the ECM provides a ground. In the TB/EV fan setup, the fan clutch used a positive signal so it had to go through a relay (SSR) first to change it around.

This is an edited diagram combining the E40 & 600W C7 brushless fan (hence 60A fuse shown):
https://i.imgur.com/jHrpm87.png

Quote:

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Originally Posted by UND_Sioux

I have a very unusual project. I won?t bore you with the details, but it is an E40 ECM running a non-LS engine.

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Does it make me weird that I really want to know all the details about this project, even if it's not really relevant? :crazy:

Attachment 92472

This is the Oldsmobile 455 out of my GMC Motorhome. It has been built with forged pistons, h-beam rods, aluminum heads, headers etc. It will be a MPFI engine with LS type engine management. I has everything needed including a custom cam and crank trigger, knock sensors, etc...