I finally managed to get the time to finish the Vette rebuild,and took it for a shake down run Friday. Runs like a champ, just one minor thing to complete. I haven't hooked up the electric fan yet. Got a 16 inch Spal mounted to the radiator, and when I tried to install the fan switch, I find it's 3/8 inch NPT, and the intake port is 1/2 inch NPT....heads are AFRs,...so no port there either.



This set me to looking at my options.

Get a 1/2 inch NPT sender? What rating? 195 degrees I guess,...(That's what I already got with the fan) Also I am finding very limited selection of 1/2 inch fan switches.....and if I do find them, they're huge. The fuel line to the carb runs right over the intake port I could use, if I do end up with a switch there. Maybe install the switch on the water pump?

Or how about one of the temperature based speed controllers? Are they worth anything? Of course I'd still need the right fan switch.

In my browsing I also found a fan controller that uses the existing temp guage sender, and has an adjustable set point. It is designed to be easily adjusted even while driving,...kind of neat,..but not a lot of room under the dash to mount things...

Also found a radiator hose adaptor to allow the switch to be screwed in to that,..., and so which hose? Upper or lower? And what rating. Should it be a colder setting than an engine mounted switch?

Or the least favorite option,...the Bubba toggle switch! Probobly not an option, unless it's just for redundancy....

So for those who've been there, done that,...What works for you, and if you have pics.....love to see them.

 

The toggle switch works for me.......mine stays "on" all the time.

 

dont do the radiator hose adapter, I have a brand new one its pretty but lame, you want it gimme $5 you can have it.. get a 1/2 to 3/8 bushing, any hardware store in plumbing, or buy a 1/2 in switch. dont use a temp sender , but a temp switch, dewitts sells spal, he doesnt mark it up in price, but there are others run every thing thru a relay.
this is a simple reliable way to do it , you dont have to use the volvo relay and those switches are all over the fleabay site.

http://api.viglink.com/api/click?for...13370422358602

 

I was thinking the hose adaptor looked kind of "rigged", and then you need a ground wire run to the adaptor too.

All these guys buying Dewitts radiators and I'm the only one that the fan switch didn't fit? I know I could have had the bung put in the radiator, but thought it would be better to keep the flow of electricity out of the aluminum radiator. As it sits, it's completely isolated by rubber everywhere.

 

just get the bushing, I did with my C4, it works great and only cost $.55 cents. The toggle switch is fun at first then it gets to be a pita . temp. switch and run it thru a relay , reliable. that link is only for reference. I did my C4 with it , cause I had two fans, But on my C3 I only used it for the part numbers of the switches. They fit the chevy holes , no issues and work fine., Hotrodders forum has a neat wire diagram , real simple.

 

Yes Sir: If you call around to different Plumbing suppliers, you will find they carry that in brass, called a flush brass bushing 1/2" X 3/8". It looks like it belongs there. Have a great one. Gene

 

Go here best kept secret

http://www.dccontrol.com/index.htm

 

[QUOTE=bozzman3;1580823003]Go here best kept secret

http://www.dccontrol.com/index.htm[/QUOTE


I ordered from these folks for my C4, and then I waited.......and waited.....and waited....and then I asked for my money back...and then I waited ...and waited...and finally got it. There's better , less expensive ways to turn a fan on

 

I also used DCControls setup.
Used it on my 05 Ram pickup and a corvette restomod I did.
Yes it took a little time to get it 8 weeks I think.
But it is a awesome setup.
Brian knows electricity

 

I have a DC Controls controller running the giant Lincoln Mk. VIII rock-thrower on my C3. Works great, and I don't recall it taking all that long to get to me. It certainly helps keep the start-up amps down on that huge motor.

 

Dewitts , along with some of the other venders, sells a nice , reliable , simple one, and he's a supporting vender on this site. Dont see DCslowspendytrolls on the supporting venders list.

 

The fan controller that I have been using for the last few years is made by Radio Research in California.
It's called Auto Cool and has an adjustable temperature setting.
The temp sensor for the controller is actully a thin curved piece of metal that mounts between the radiator inlet or outlet and the hose. I assume that its some kind of thermocouple.
They used to sell them on e-bay, but dont seem to do that any more.
The easiest way to find them these days in on Los Angeles' Craigslist.
Here is a pretty current link http://losangeles.craigslist.org/lac...014604495.html

 

A few weeks ago I installed a Mark VIII dual speed fan and was looking at many options regarding the controller. I ended up with a Hayden set up from summit racing for $49 and it works great. I set it to engage the low speed at 170 degrees and at 180 it turns the high speed on. Works like a champ, mounted it on the fender well under the hood support above the control arm and inserted the temperature probe in the radiator close to the upper hose.

http://www.summitracing.com/parts/HDA-3654


.

 

I used the flex o lite control that uses a probe going in the radiator hose. Bend the probe around the top radiator port and use some electrical tape then slide the upper hose on.
There is other sensors that slip in the radiator fins or wire tie to the thermostat housing. You can also use the stock electric fan thermostat switch near the starter but I think it kicks on at 210*+ but they sell a lower setting in the catalogs. This would be the cheapest way to go.

 

Which controller did you get? I only have one fan, pulls 22 amps, so the smaller controller would work I imagine.

I like the idea of speed control because it gradually comes on, as the temps rise. The relay controls are all or nothing,...so you sit at a stop light watching the temps climb to super hot,...then the fan kicks in.

 

the variable speed controls are excellent but something I learned while researching for the dual fan setup on my C4 and that I've now installed with the dual fans on my C3, is that the turn on switch or setting for the low speed fan needs to be at least 10 degrees less than t-stat opening or it will always be trying to catch up and will never shut off , no matter what system you use.
btw, if you want the best one out there...not a vsc though

http://www.dakotadigital.com/index.c...rod/prd641.htm

... nothing else comes close

 

That doesn't happen if the sensor/switch is located a the radiator exit (cooled coolant) and set accordingly.

 

When I bought mine, only the original Auto Cool existed (that I know of).
It doesn't do variable speed, and only has a 30 amp rating.
I actually have mine wired to trigger a 60 amp relay since I run the Mark VIII fan.
I do like the looks of the Auto Cool II though. I may have to upgrade.

 

Sorry if I'm getting a little off subject here. Do you guys have any issues starting the car (getting gas or running into a store real quick) after it has reached the set temp. Once my car reaches fan operating temps and I kill it, it struggles to crank over. The circuit the controller runs off of is still grounded because the engine is still above that temperature. So when I have the ignition turn on the accessory side the fans come and I'm assuming it's struggling to start sometimes because of the fans drawing the initial amperage and not the starter.

I'm running some ford focus fans and a dual relay controller setup from jegs with a thermostat controller that mounts in intake. My ignition wire for the relays are hooked up and power is pulled from starter terminal. Alternator and battery have been tested and in good shape. I have upgraded alternator to the 140amp cs144 to keep up with fans, hid's, and so on. Starting issues didn't occur until I installed fans, so I doubt it's starter solenoid.



Thanks!

Ryan

 

Ryan I'd say you need to inhibit the fans during crank. Look for a alternate power tap that isnt hot in crank,but hot in run or accy