Author Topic: Installed electric fan temp switch last night (Read 542 times)

Fast68back · « **on:** March, 25, 2009, 08:08:34 AM »

Got the bracket in the mail yesterday for the temp switch. here are some pics, disregard the wiring mess, now that its in I can connect it and clean up the loose wires. Once I get it set I'll probably remove the knob, with the round headed screws I doubt it will stay on very long, either that or I'll replace the round headed screws for some flat headed ones to gain more room for the knob.

tarafied1 · « **Reply #1 on:** March, 25, 2009, 10:44:40 AM »

so it's an adjustable on/off temp?

Fast68back · « **Reply #2 on:** March, 25, 2009, 10:56:03 AM »

Honestly, I'm kinda confused by it. There are no indicators on the dial, so I cant set it at a certain temp. I guess I have to let the car run and when it reaches a certain tempurature, I turn the dial until the fan kicks on, once the car is below the temp the fans will kick off.

daveSanborn · « **Reply #3 on:** March, 25, 2009, 02:28:15 PM »

Be sure to wire the fan relay so that it's only energized with a 12v switched power source.

Fast68back · « **Reply #4 on:** March, 25, 2009, 03:07:16 PM »

It is, I ran a keyed source to the dash (plan to hook it up tonight). It was part of the reason I added the painless powerbraid. I didnt want to unwrap the stock harness, so I taped the wire to the harness and then covered it up with the powerbraid.

OK, now that I think about it, is that the right thing to do? Say for example I set the switch to kick on at 180 I drive and get where I'm going and its at 179. I park and turn off the car. Why do newer cars run after you get out of them? If it was constant 12v the fan would run until the car cooled to the shut off temp, no?

tarafied1 · « **Reply #5 on:** March, 26, 2009, 07:58:53 AM »

My fan relay set-up had a yellow wire that was to be wired to the key (ignition) and a constant hot wire. I have a temp switch that comes on at 185 and goes off at 165. I went ahead wired the constant hot wire to my junction block and then wired the yellow wire to a seperate 12v in the junction block but I have a toggle switch under the dash. This way when I shut the car off, if the fan is still running I can decide if I want to leave the fan on or not and still take the keys out of the car. My car has actually been running without the fan and then when I stop and shut it off, it will sit a minute or two and then the fan kicks on. I don't mind that it does but I thought I'd rather have the option to make sure it wont kick on while unattended if there were some reason to worry about that, otherwise I just let it do it's thing.

70_Fastback · « **Reply #6 on:** March, 26, 2009, 10:31:32 AM »

Mine used to be ran to a constant 12V source; and it would run until it hit it's set point.

But I changed it, all because of the little label on my fan shroud...

It says: "Caution Fan May Run Any Time Ignition is On"

So I changed it, to a switched 12V ignition source, due to my O.C.D. :crazy

daveSanborn · « **Reply #7 on:** March, 26, 2009, 11:45:37 AM »

I posed the question of "should I wire the fan to a constant 12v source so that the fan will come on (and stay on) until the temp falls below the set point regardless of whether the car is running or not" to one of the BeCool customer service reps while we were discussing other issues. He was an old timer and a straight shooter and I loved talking to this guy.

His answer to me was:

Why in the world would you want to keep the fan running after the car was shut off? Water is no longer circulating through the engine and the only thing getting "cooled off" would be the coolant that's stagnant inside the radiator. Besides, the fans amp draw is too high to leave it running for too long on battery power alone.

I appreciated and followed his forthright advice and wired my fan (and all subsequent installations) to a keyed source.

Fast68back · « **Reply #8 on:** March, 26, 2009, 12:10:47 PM »

Quote from: daveSanborn on March, 26, 2009, 11:45:37 AM

I posed the question of "should I wire the fan to a constant 12v source so that the fan will come on (and stay on) until the temp falls below the set point regardless of whether the car is running or not" to one of the BeCool customer service reps while we were discussing other issues. He was an old timer and a straight shooter and I loved talking to this guy.

His answer to me was:

Why in the world would you want to keep the fan running after the car was shut off? Water is no longer circulating through the engine and the only thing getting "cooled off" would be the coolant that's stagnant inside the radiator. Besides, the fans amp draw is too high to leave it running for too long on battery power alone.

I appreciated and followed his forthright advice and wired my fan (and all subsequent installations) to a keyed source.

Works for me! Anyone asks I'll say Dave said so.........

70_Fastback · « **Reply #9 on:** March, 26, 2009, 12:15:08 PM »

Or say your OCD. It works for me. People leave me alone.

tarafied1 · « **Reply #10 on:** March, 26, 2009, 12:19:47 PM »

I don't completely agree. The coolant is still connected (although it's tru a hose). If the rad coolant temp drops, there will still be some heat transfer. Also the underhood temps can rise right after shut down. If the fan(s) are cooling, it can help cool the under hood temp as well. If you park the car for the day/night it may not be a big deal but lets say you are driving to a cruise night. You stop at the local choke-n-puke to get a slider and pump a little petrol in the tank (eat and get gas). You only stop for 20-30 minutes. My big 429 with 10.5:1 is bit cranky (pun intended) when you ask it to refire under such conditions. I don't have any scientific data to prove it but I think the continued cooling during shut down can make for easier restart in a short stop condition... just my opinion and we all what opinoins are like.

70_Fastback · « **Reply #11 on:** March, 26, 2009, 12:22:24 PM »

Interesting perspective as well.

tarafied1 · « **Reply #12 on:** March, 26, 2009, 12:23:04 PM »

one other positive note, my car tends to attract a crowd when I arrive somewhere and park it. It's a bit of a deterent for nosey people when things kick on and off by themselves...

daveSanborn · « **Reply #13 on:** March, 27, 2009, 12:11:56 PM »

Quote from: tarafied1 on March, 26, 2009, 12:19:47 PM

I don't completely agree. The coolant is still connected (although it's tru a hose). If the rad coolant temp drops, there will still be some heat transfer. Also the underhood temps can rise right after shut down. If the fan(s) are cooling, it can help cool the under hood temp as well. If you park the car for the day/night it may not be a big deal but lets say you are driving to a cruise night. You stop at the local choke-n-puke to get a slider and pump a little petrol in the tank (eat and get gas). You only stop for 20-30 minutes. My big 429 with 10.5:1 is bit cranky (pun intended) when you ask it to refire under such conditions. I don't have any scientific data to prove it but I think the continued cooling during shut down can make for easier restart in a short stop condition... just my opinion and we all what opinoins are like.

Craig, this was my exact logic when questioning the BeCool rep. As long as you have a strong battery, I don't really see how it would matter one way or the other.