Rebeldryver's '65 Impala SS Black Betty

[Scott Liggett]

Ordered up a pair of 1390 cfm Spals, wiring harness and circuit breaker. Got a great deal.

Ran wires to eliminate ignition issues. Still have one other wire to do, but need light to do it as it runs down behind the motor and it's in all my nice wire looms. Ugh.

Also, while getting a crick in my neck under the dash, I eliminated an area around the column that allowed warm air into the car. Not sure what happened to the seal around the base of the column.

[Scott Liggett]

Started to replace electric fans and wiring for them Monday.

These are Spal's 12 inchers that pull 1390 cfm each. These were actually on this shroud when the radiator was in the previous owner's car. The holes lined up perfectly.


The lower radiator hose outlet is at a 45* angle and it was hitting the fan's shroud for some reason. I did a bit of clearancing on the shroud. I'm not sure why the fans were hitting the lower hose before the bolt holes lined up. Maybe the old Spals had a different design. I ended moving the whole fan shroud set up to the left about a 1/4" to give the fans and lower some space. Because I would have to butcher one of the fans in order to get the bolt holes lined up.



I got the Spal wiring harness, relay and a circuit breaker for rewiring. So I removed all of the old fan wiring I had with old fans. But, I ran out of time to actually start wiring. I also want to get another piece from Spal before going forward.

[yellomalibu]

Just one relay for two fans?

I like having one relay for each fan. I don't know if two fans would overload the relay - it's just that if one fails, there's another one.

*edit* (so my post isn't taken as a negative post :-) ) Glad to see you working on it again! I love seeing progress. It keeps me motivated to keep working on mine.

[Scott Liggett]

I thought the same thing, but I am following Mattson's advice. There is a circuit breaker between the relay and the car battery for using two fans, I think. I have to look at the wiring diagram again. But, the circuit breaker replaces the need for the second relay.

[milner351]

Are the fans triggered together by the same switch or does one come on a xxx temperature and the other come on only if the temp reaches some higher value?

Most OEM dual fan, or dual speed, set ups are wired up to run one fan on a temp switch, the other when the AC is used or a higher temp threshold is reached. Running two fans full time is a big amperage draw, you may find that it "short cycles" when the ambient temps are low.

[Scott Liggett]

This car is not oem. It does not have AC. They will be triggered by an on dash switch for now until I can figure out where to put a temp sensor. And, no there is not any ports in the heads. The only port available for a temp sensor is being used by the temp gauge. No, they dont make a straight water neck that has provisions for a temp sensor. The only ones are at 45* pointed the wrong way. I may have to put a spacer under the water neck. Or, drill and tap my cast iron water neck, if possible. My alternator doesnt have any issues running them.

[milner351]

Scott - anyway you can put some sort of T fitting into the port where your temp gauge goes and run both the fan and temp gauge probes in the same port? I've also seen some guys run a short section of pipe in the upper hose with a threaded bung welded for a temp probe.

[Scott Liggett]

Scott - anyway you can put some sort of T fitting into the port where your temp gauge goes and run both the fan and temp gauge probes in the same port? I've also seen some guys run a short section of pipe in the upper hose with a threaded bung welded for a temp probe.

I thought about having a bung welded into one of the upper hose pipes. We will see. I will only need to move one wire to add the temp switch in the future.

On my trip to Norcal, I shut the fans off while on the freeway. No big deal for me.

[milner351]

you're a very attentive driver - my mind drifts some times and I go too long without watching the gauges. I've had electric fans on a few cars and in most cases they never came on at highway speed.

[Deaf Bob]

I have a brass section that has a bung already in it... Now if I can just remember what it came off of...

[Loren]

Can't put a temp sensor in the upper radiator hose, it's got to be upstream from the thermostat. Can't use a tee either, the sensor has to be in the flow. Where I've wanted an additional, I drill/tap (pipe thread) a hole in the intake along the crossover.

Not that everybody has to do it my way, but on my Chall where heat issues have to be thought about I have two sensors in the intake, each at a different temp trigger, with their own relay and fan, and a indicator light on the dash. One comes on, then the other. Works for me, no flippin' switches while driving.

[milner351]

Makes sense Loren - do you suppose the sensors I've seen were for a gauge in the hose? Or just installed by miss-guided folks?

There's lots of them out there with a probe in the radiator fins - but that's never seemed like the best way.

[SuperBuickGuy]

This has really got me thinking about my system on the Corvette. I could make one fan go on with a dummy temp sensor, then program the other to come on through the FAST system.... hmmmm, thanks for bringing this stuff up, John (and Scott )

[Loren]

Then for the relays, one side is wired to run+, and then a ground from your sensor (I keep saying sensor when I mean coolant temp switch)kicks it.

Makes sense Loren - do you suppose the sensors I've seen were for a gauge in the hose? Or just installed by miss-guided folks?

There's lots of them out there with a probe in the radiator fins - but that's never seemed like the best way.

I don't know why anybody would have a probe in the radiator hose, but having one stuck in the cooling fins makes sense. After all, if the water in the radiator is hot then the fan could/should be on...if it's not, no fan needed.

[Scott Liggett]

Then for the relays, one side is wired to run+, and then a ground from your sensor (I keep saying sensor when I mean coolant temp switch)kicks it.



I don't know why anybody would have a probe in the radiator hose, but having one stuck in the cooling fins makes sense. After all, if the water in the radiator is hot then the fan could/should be on...if it's not, no fan needed.

I had a cheap Hayden probe type with an adjustable temp on/off for years with the old pusher aux. fan I had in front of the radiator. It finally died a couple years ago. I always had the switch with indicator light because at freeway speeds the aux. fan would block air going into the radiator if it was on.