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-   -   SPAL-PWM-V3 & Black Magic 150 Install (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/spal-pwm-v3-black-magic-150-install-851238/)

jackhild59 10-22-09 11:46 AM

The Spal v.3 unit retains the design flaws? Glad I didn't buy that one.

RotaryRocket88 10-22-09 01:30 PM


Originally Posted by Aaron Cake (Post 9577853)
Cut the ground wire eh? Good to know that SPAL is still producing a circuit with a major defect as this is the exact same advice they gave me due to their old circuit sharing a signal and power ground.

You're making me want to get the new version as it sounds like it's working for you. This winter I'll be losing the extra output on my Microtech in favor of using it to drive the BAC valve so I'll need some way of controlling the FAN. But it's hard to justify spending another $130 on top of the $80 I have already spent on the previous version especially when it sounds like SPAL still didn't get it right...

The 'cut the ground wire' suggestion was only for use with their temperature sensor. Since the wire is actually redundant (grounded through chassis too), there's apparently the theory that it could be causing interference. But given the results, it doesn't look like that's the case. The unit measures resistance, which is used to determine if current draw has increased over 25A, so it looks like they just made it too sensitive.

Oddly enough, I didn't run into the shutdown problem at all until I put the FD alternator in. The alt's voltage output has been logged and fan current draw re-measured, so I don't know if it brought on the change, or if it was coincidence.


Originally Posted by jackhild59 (Post 9578052)
The Spal v.3 unit retains the design flaws? Glad I didn't buy that one.

Minus the overcurrent protection feature (which I don't need anyway), it's been performing perfectly. Though I would suggest to anyone that does buy one to just go ahead and have the circuit disabled before installing it.

jackhild59 10-22-09 02:12 PM


Originally Posted by RotaryRocket88 (Post 9578233)

Minus the overcurrent protection feature (which I don't need anyway), it's been performing perfectly. Though I would suggest to anyone that does buy one to just go ahead and have the circuit disabled before installing it.


Is the overcurrent protection intended to protect the fan or does it protect the Spal unit?

I assume you have the circuit fused as well?

RotaryRocket88 10-22-09 06:08 PM


Originally Posted by jackhild59 (Post 9578310)
Is the overcurrent protection intended to protect the fan or does it protect the Spal unit?

I assume you have the circuit fused as well?

It is intended to protect the controller, since it is not designed to be run with fans that pull 30A or more. And yes, the whole thing is fused, but the fuse never popped on me.

rotarygod 10-23-09 09:20 AM

There needs to be a way to disable the fan above a certain vehicle speed as at some point there will be more air coming into the car from forward movement than the fan can push. At that point, it's not doing any good and is only doing harm. This is why locked up clutches on mechanical fans is a bad thing. They overheat at speed. Have you seen any issues at freeway speeds for extended periods of time?

clokker 10-23-09 09:29 AM


Originally Posted by rotarygod (Post 9579917)
There needs to be a way to disable the fan above a certain vehicle speed as at some point there will be more air coming into the car from forward movement than the fan can push.

Isn't that basically what the temp trigger switch is doing?

jackhild59 10-23-09 01:49 PM


Originally Posted by rotarygod (Post 9579917)
There needs to be a way to disable the fan above a certain vehicle speed as at some point there will be more air coming into the car from forward movement than the fan can push. At that point, it's not doing any good and is only doing harm.



At what speed is the cooling fan unnecessary? 40 mph? 60 mph? :dunno:

Would a 25 mph tail wind affect that? How bout a 30 mph head wind? What about a 100* day or a freezing temp day?

RotaryRocket88 10-23-09 02:18 PM


Originally Posted by rotarygod (Post 9579917)
There needs to be a way to disable the fan above a certain vehicle speed as at some point there will be more air coming into the car from forward movement than the fan can push. At that point, it's not doing any good and is only doing harm. This is why locked up clutches on mechanical fans is a bad thing. They overheat at speed. Have you seen any issues at freeway speeds for extended periods of time?

No, I don't have any cooling issues on the freeway. It's a rock-solid 180F. The stock mechanical clutch would be locked up at that temperature still, if the temp range I quoted earlier is true (160-180F). Beside that, something like ALL of the cars rolling off of the assembly line today use e-fans. Do any of them have a vehicle speed-sensitive fan controller? It seems unlikely.

rotarygod 10-23-09 02:40 PM

No clue. Just asking. I know some aftermarket electric fan shrouds have little "valves" for lack of a better word that open if pressure through the radiator exceeds a certain amount, regardless of if the fan is running or not. All that matters is results and it appears to be fine.

jackhild59 10-23-09 03:47 PM


Originally Posted by rotarygod (Post 9580530)
No clue. Just asking. I know some aftermarket electric fan shrouds have little "valves" for lack of a better word that open if pressure through the radiator exceeds a certain amount, regardless of if the fan is running or not. All that matters is results and it appears to be fine.

I agree completely. Those valves of flaps are designed to allow increased airflow when the fan is off. They won't be open if the fan is running.

One of the reasons that I have recently changed from my Taurus fan to the Mark VIII fan is the Mark is 18". It literally goes from top to bottom, from tank to tank with fan blade. It has more fan than shroud so the open area is quite a bit higher than my old 15-16" Taurus fan. I think it will allow a little more airflow when the fan is off.


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