Hey everyone. I just completed cam break in on my new 350. I am completely off the computer. There was a connector that plugged into the head that would cause the fan to turn on and off, but the connector broke off (I'm assuming when I pulled the old motor). How can I rewire this to make it work correctly? The fan will turn on when the wire is grounded. Does anyone have any suggestions?

Also, I'm probably going to need a new radiator. I don't think mine is large enough to properly cool this motor. Any suggestions on that would be helpful as well.

 

what was the original motor in the car? if it was the 305, then you would have a fan switch on the passenger side head. it grounds the fan relay when it gets hot enough, turning on the fans. if you broke that peice, go to the auto parts store and get a rplacement. if you broke the connector, then you can try and snag one from a jy car and splice it into the wire. or you can get one that turns on at a lower temp that has a normal male spade connector on the end, put that in, then just crimp a female spade connector on the stock wire.

 

and your radiator will be fine as long as its in good working order.

 

travis,

I no longer have the female connection. Currently, I have the wire grounded to the engine with a pair of vise grips to make the fan turn on. How would I set that up (connector, switch, whatever)?

 

youd either have to get one from a donor car. or replace the fan switch with one that uses a standard male spade terminal. thats what i have now, i even got one that turns on at a low temp, since the stock one triggers the fan at 230.

http://www.summitracing.com/parts/HFM-ZFSWF/ thats the one i use, turns the fan on at 190 and off at 180

 

got it, thanks a lot for your help!

 

quick question regarding the switch - does it have to be located in the head for it to work properly, or can i put it in the intake? I have a hole in the intake that is currently plugged. The plug in the head is proving to be difficult to get out.

 

in the intake is fine, as long as its before the thermostat.

 

hypertech makes a cooling fan switch for around 40$ through summitt alos u can get a proformance radiator that would help

 

is the fan controlled by the computer as well?

 

in a dual fan set up and on the v6 yea. it may be some other applications it is as well. but as far as i know the v8s with single fans are controlled by the temp switch and by the ac.

 

The reason I ask is because I hooked it up and the fan wouldn't turn on. But if I manually ground that wire somewhere, it does. The switch is brand new.

 

all the switch does is ground out at a set temp. if the fan works when you ground the wire but not then plugged into the switch then that points to a problem with the switch. how hot are you letting the car get to test it?

 

and what switch did you get?

 

I got the temp thing that screws into the head (between 6 & 8), which I first installed into the intake. It didn't work there, so I put it into the head (between 1 & 3). Temp gauge says approx 240 before I kill it, however, I am not sure if this is accurate.

It looks like the item here : http://www.summitracing.com/parts/HFM-ZFSWF/?rtype=10, except for a male connection, it's a female tube.

Oh, and it is a stock item, so whatever temperature that is is what the switch is supposed to do.

 

stock replacement turns the fan on at around 230. it could be the the gauge isnt accurate. or you got a bad switch

 

let the car run untill either the fan turns on, or you start to get water boiling over into the overflow tank.

 

letting it get that hot isn't going to cause problems? I only ask because if i wreck this motor, my wife will make me sleep in the garage.

 

if it does start boibling over shut it down and let it cool. letting it get that hot for such a short period of time isnt gonna hurt it

 

10-4, i'll give that a shot.

 

water boiled into the overflow tank before the fan turned on. it boiled over at approximately 250* (as shown on the gauge). does that sound like an inaccurate gauge, bad switch or both?

 

gauge is about as accurate as it really needs to be, sounds like a bad switch or possbily a bad connection from the wire to the switch

 

Will the operation of the switch make a difference if I had to use a 3/8 to 1/2 npt fitting to install the switch? It kind of makes the "thermostat probe" part of the switch sit inside the fitting, but it should still be surrounded with water.

I am also running straight water right now so I'm not dumping coolant all over the place. Will this matter either?

The wire I'm using is black, and it runs up into the harness (difficult to trace now that the motor is in). Is there another wire that's supposed to be running to this?

 

the fan relay should have a green wire with a white stripe, thats supposed to go to the fan switch. the black wire is the ground and needs to be hooked up all the time. and the adapters are fine as long as the water can flow into it and touch the switch, and stright water actually cools better than a 50 50 mix, but it corrodes parts.

 

does the connector get both black and green/white? currently the connector is only hooked up to the black wire. do you have time to talk on the phone? I'll call you so you don't get charged.

 

it should only have the green wire hooked up to the switch. the black wire needs to be hooked up to a ground.

 

Travis, I traced the green wire from the relay. It's hooked up to some kind of 4 prong connector with other wires running to it. the connector has wires running from it and they run directly into the firewall below and to the left of the heater hoses. That wire does not have a white stripe on it. Should I cut it before the connector and hook it up? I'm assuming the other wires are running to the computer?

 

those wires are for the AC. can you post up some pics of the relay and the wires?

 

Relay


Harness from Relay, front and back (so you can see the wires)


4 prong connector the green wires runs to. The correct green wire is in my hand to the left of the connector.


These are the wires running out of the connector into the firewall.


If you need anymore pictures, let me know. It starts to get dark here now around 7pm eastern daylight.

 

so i looked up a wiring diagram just to be sure, but that dark green wire is the relays trigger wire. the other end of that should be attached to the coolant fan switch. but the diagram shows a black wire comming out of the switch so that doesnt make much sense. either way, of you hook the fan switch into that green wire, it should work, as loing as the switch isnt defective.

http://www.austinthirdgen.org/mkport...ine_wiring.gif

 

travis,

hooking up the green wire worked to turn the fan on. the black wire did not need to be hooked up to a ground at all. I think it had something to do with the dummy lights that were originally in the car. The picture shows the green wire with the black wire spliced in by the factory, to explain the wiring diagram.

Thanks for your help, it has been much appreciated.