seanrot

iTrader: (2)

OK, I awhile back I asked on the wiring digram on a relay and thanks for the input. I got my fan and ignition wired up and running.

Now, I have removed most of the wiring from the passenger side harness. This left me that little choke control switch in the waterpump housing and no purpose for it.

I took my multimeter and came to the conclusion that it has continuity when cold and when hot it's not. What I mean by continuity is if I take a positive input to one of the wires in the switch, that input will flow out the other wire until the switch reaches a temperature that it would normally release the choke.

Here is my thought.

Relay diagram

85 switched positive <-- connected to the fan
86 ground
30 positive in always hot battery
87 output of 85 positive when switch connect positive source<--- Not used this is what I have now turns on with the key
87a output of 85 positive when not connected to positive source <--- connected to choke switch with positive input

I believe this would give me a cheap mans semi control of the electric fan. Should keep the fan off till the engine reaches operating temp, but thats about it.

What you think inputs needed might be my weekend project....

seanrot

iTrader: (2)

I was just thinking about it, I dont think it will work. I think 87a needs to be grounded to provide 85 with a positive out. I think I'm going to have to get a relay and start playing with it.

How can I wire a relay to give a ground signal...With the info above?

Pele

iTrader: (28)

I gotcha covered... I don't have the time to draw a diagram right now, but gimmie till later tonight.

Stick a PM in my box to remind me...

And I've always hated that 85, 86, 87, 87a, 30 listing for Realys... WTF do they do that for?

Call em C1, C2, NO, NC, and COM...

Anywhozer... Lemmie go into description here...

Two connections to the coil... One goes to the temp sensor, the other goes to Ignition switched + source... There'll be one free connection on the temp sensor; Ground it.

On your relay, Normally Open goes to Ground, Common goes to your fan motor. Normally closed goes nowhere.

One extra lead on your fan... Stick that to a fuse and to +12 volts.

If you wanna reverse things, Normally open on the relay to fuse and +12 volts, and the free lead on the fan motor can be grounded.

Like I said, diagram coming tonight or later sometime.

seanrot

iTrader: (2)

I was just looking at the factory manual and the switch looses continuity at 157 +or- 11.7 degrees F. Sounds like a good place to start a fan.

seanrot

iTrader: (2)

Thanks for the write up. Cant wait to see the diagram so I can relate the numbers on the relay to the c1 c2 no nc and com

I'm feeling a little stupid, show me picture I can make

Thanks again,
Sean

85rotarypower

So this relay allows power through at a certain temp but doesn't turn off again? If it would only turn off at that same temp again it might work as a switch for the fan. No more toggle switches and aftermarked probes.

seanrot

iTrader: (2)

I would assume that it would let the power though again when the tem drops. If your enging temp dropped below 157. I dont think there would be much chance of that happening while the driving.

Anyone have one of these not in a housing and would like to put it in hot water on the stove with a continuity tester and a thermometer?

I'm really just tired of the fan being on when I start the car. This would delay that till engine hit normal operating temps I believe.

85rotarypower

It would still be usable though. If it turns off again when the temp goes below 157, then thats great. You might just be able to add a resistor in the line somewhere to raise that temp point to 180. Then it would be very usefull. It would require some testing, but it might be possible. The resistor would delay the time at which the continuity is there, and therefore make it work at a higher temp. Am I just talking stupid here? Or do I have a good point.

Jeff20B

iTrader: (13)

Interesting stuff.

Hades12

The sensors internal resistance is what would determine the on/off point. An extra resister would just drop current and voltage across the sensor.


Also thought of something else. with this temp sensor the fan will start on or before the thermastat has opened. Meaning it will be cooling the Rad before it gets hot. The after market probes us the rad temp to turn on.

seanrot

iTrader: (2)

Dont they sell a low temp thermostat for thats set for 160. This would be just right.


Thanks, I just had that connecter hanging there figure might try to see it it could be used for something. Specially since I looked though the VB catalog and saw that sensor was like $150.00 (if i remember correctly, getting old).


Are you say this is a bad thing? It sounds kinda like a good thing to me.

Hades12

Just making a statement.


Also If you wired the relay to the battery inplace of the ignition the fan would run until the temp went down, even after you turn off the car.


I did a drawing of the wiring but cant upload it to the board. Keeps timing out.

seanrot

iTrader: (2)

I think it might take awhile for the engine to cool down to 157 degrees (dead battery). That and it mainly cools the radiator and since the waterpump isnt pumping. I dont think it does alot for the engine.

85rotarypower

It was worth a try anyway. I don't totally understand how a resistor works, but I thought I would try. Is there mabey a way to change the temp at which the sensor turn "on"? Probably not, but just think about it.

seanrot

iTrader: (2)

I think we would be stuck on the turn on point other than each switch being different in itself. the manual says +or- 11.7 degrees.

Also, just stepped out the library after going through the VB book. I think I was mistaken on the price of the sensor. I couldnt find it oin the book and all I saw in the price range was the list price for the oil level sender. Opps my bad on goes the flame suit. Well, After a long day at work i'm home now and going outside to see if I can start an electrical fire with this setup. Ill keep you posted

seanrot

iTrader: (2)

OK you guys are not going to believe this. I have no electronic background so this should amaze the **** outa ya. Excuse the French. I have been working on just figuring out the wiring for the last 4 hours.

You Need THREE relays to do this.....looking at me like I'm nuts now right!!!


There it is and buddy that was a pain to figure out. The problem is that your switch starts in the on position. No matter how I wired one relay the power would start as soon as you started the car. I had to change that so when the thermal switch turns on relay #2 it turns off relay #3. Then when the engine heats up the thermal switch actually turns off and so does relay #2 in turn activates Relay #3. at this point your fan should be turning quite happy like. Now what is relay #1 for???? Anyone???? Relay #1 is acting like a switch for the battery power to Relay #3. remember Relay #2 turns off relay #3 so if relay #2 has no power when you turn the car off Relay #3 is going to keep the fan on. So Relay #1 kills the power to #3 inturn shutting the system down. Know wasnt that fun.... Imagine all you had to do was try and read it......I need a

BTW relay 1 and 2 can use the same fused battery lead. there is no need for two seperate ones

Also, I havent actually hard wire the car yet that will be tomorrow.. I was working with it in the house with the relays, a 12v battery charger and multimeter. I played with these till I finally got the results I was looking for....

seanrot

iTrader: (2)

Can you believe it I may have just made a worth while contribution to this forum!!!!

Directfreak

iTrader: (2)

OUTSTANDING!

Pele

iTrader: (28)

Congratulations. You turned all power to the fan off when the key is on... Slide that connector from 87 to 87a on relay 1.

Sorry... Smoked a little too much last night... I'll get that diagram to ya later... Mine needed one relay.

seanrot

iTrader: (2)

Sorry Pele to disagree with you. but if I change from 87 to 87a I will have power to the relay when the key is off. 87a will provide direct power without and input signal(switched) NC normally closed power out. So, tuning the key sends the power through 87 NO normally open. Which provides the main power for the fan though relay 3.

I'm going to get some shrink tubing and connecters and wire this up.

Hades12

I think you can do the same with only 2 relays.

by connecting them in series. one closes the circut then the ignition is on and one closes the circut when the temp sender is off. so that the fan only runs when the ign is on and sender is off.



relay one, coil to ing to ground.
Fan ground to NO, Common to second relay.


relay two, coil to ing to sender to ground.
common from relay one to NC to ground.


of corse I may be wrong.

Jeff20B

iTrader: (13)

I think I might try this on one of my vehicles some day.

The way I'd do it is to have the fan come on when the temp gets up to 157, and then stay on untill the key is turned off. I'd also wire in an overide switch to turn the fan off briefly while cranking the engine, if it's during a warm or hot start. You know, any time the fan decides to run when you don't want it to.

Wiring in a relay or two is an afterthought at this point. Well, for me it is. I'd have to plan everything and go from there. Sorry I can't add anything to the diagram that's in this thread.

Edit: Yeah, I'd install one of those momentary push-button switches in the dash on the left side near the choke. It would kill the fan while cranking the engine so maximum power can be available to the starter. No point in running the fan on a warm, but cranking engine.

A brake light switch would work. It only makes contact internally when not pressed. It would only need to carry a small amount of power which would go into the switch side of a relay. The load side of the relay would go from the battery to the fan motor.

seanrot

iTrader: (2)

OK gents good news and bag..... good news is that me relay system above worked exactly as it was supposed to. sensor switch grounded fan off no ground fan on. So, in the world where my damn thermal switch worked I would have been a happy camper. Does anyone have that switch and would like to donate it to a worthy cause???

Just a heads up no matter how hot my engine got the switch never lost continuity. I turned the fan on manually when the temp guage got halfway. meaning that bastard didnt work!!!. Need a new switch.... bugger..

I think I will look at the wiring diagrams never know it might need a positive lead running though it...

Pele

iTrader: (28)

Sorry.. I can't find a Paint like program for my Mac... When I get my PC back I'll do a diagram.

Pele

iTrader: (28)

Hmmm... This is why I hate the 85,86,87 designations for the relay contacts... I'm ignoring them and looking right at your diagram.

Relay 1... Turn key on, coil moves switch... Switch conects to LEFT contact which has nothing on it... Right contact has no power to send to 30 on Relay 3, and hence no fan...

Can anyone tell me why these numbers are designated for relay contacts? Here is a perfect example for them to be thrown out... Or for me to learn the designations.. One or the other. heh.