My fan never worked right so I hooked it up to a toggle switch about mid summer last year. Since then every time I drive it the wires get very hot because of the alternator. One time smoke started pouring out from under the dash. It burned the electrical tape right off and the wire was fryed in two. Do I need a resistor? And where could i get one? And how to install?

sounds like a faulty fan motor pulling to much draw....

maybe. That thing really gets on my nerves. Up untill two days ago I had to hit the switch and pop the hood and move a wire to get it goin. Then it stops working when im driving, overheats, then its back on. Im gonna get a dual fan setup when i park it for winter soon and rewire the whole thing but I need it to work for now.

junkyard fan man, you really dont wanna lose cooling in traffic on a hot day, also do you have a relay set up on it?

I have wired straight to the battery. But the original relay is on the car still. I had to wire it up fast because I started school in less than 15 minutes that day. I just havent had the time to do it right. I actually got behind a wreck and sat there for 10 minutes the other day and sure enough the fan quit. Went past 220 the in about 2 more minutes smokes pourin out the overflow. I was very angry at that time.

Sounds like you have a wiring problem. I mean it very well could be a bad fan as well but since this is a custom set up and you said ever since you hooked up this toggle switch you've had these problems i would want to confirm that your set up can work as incorrect wiring can kill the fan among other things. For starters what gauge wires did u use and what was the amp rating on your switch? Do you have a schematic? You really should have a fuse installed. I wouldn't drive the car as not only can you lose the fan and over heat that could cause an electrical fire and i don't know of many things that burn as well as cars do.

You need a relay.. Simple as that.

Is at atleast fused?

also make sure you are using the right gauge wire i messed up one time and i think i used 14 and it caught on fire.

It is fused. Never blew it. I know i used the wrong guage of wire but I had to use what I could at the time. I need 0 guage right? Im gonna fix the wiring a soon as I can but I have to drive it every day to get to my welding class. The switch is a 12 volt. I found all i need at auto zone as far as wires and switches but i need to get a dual fan at the junkyard. Ill need help with that on how to convert from single to dual.

Well using the wrong gauge will cause more damage than its worth not only does it present the risk of starting a fire but because the large voltage drop in the wire cause by the inadequate gauge wire the voltage will be much lower at the fan causing it to burn up in short order as electric motors dont like running on low voltage. As far as the switch rating what i was more concerned with was the amp rating? Lastly on a stock motor or even close to stock you really shouldn't need a dual fan set up as nice as that would be if you could find one cheap enough. If you need a dual fan set up to keep cool chances are you have some other underlying problem. Course I think you'll find that to get a dual fan set up with the brackets and all will be a good bit more expensive than just replacing the stock fan. Why not just fix the factory fan set up?

in order to stop burning wires, you need a relay man, wire the switch to ground the relay and let the relay do the rest of the work, i believe the wire going to the fan is actually 10 guage, hook it up right or your gunna be in a world of hurt when you blow those head gaskets

Actually he dosnt really "need" a relay as long as he has wires with an adiquit gauge for a given length and current draw and a switch with a high enough current rating. Typically a relay is used because the ECM (or other control circuit) controls the fan and the ECM (or other control circuit) obviously cannot power a fan. So they use relays to allow a low power circuit to control a higher power circuit. In his case though he shouldn't need to get into that added level of complexity of adding a relay however again thats only true if he uses the appropriately size switch and gauge wire obviously.

agreed its not NEEDED, but he already has one under the hood of the car most likely, why not use it? all he needs s to hook his fan back up to it and run a wire from a switch, instead of running 10 or 8 gauge wires through a gaping hole in his firewall to get to it, a relay is much mroe stable, wayy less likely to burn up the wires and his switch will be able to handle it., its really not rocket science

Very true but he said his fan didnt work which is why he made this switch set up in the first place. So why try to use the old stuff when it didnt work in the first place? Sure he could make the necessary repairs to the circuit so that it could be wired up like that but that would make the whole installing a switch thing completely unnecessary if he was going to fix the circuit. Personally ide just repair the existing circuit and have it work the way it was meant to but to me my second choice would be to bypass the factory stuff all together. Reliability through simplicity.

well if you look, he has a 305 TBI, those cars rely on a single fan that turns on using a switch in the passenger side head, NOT ECM controlled, all he really had to do was ground the black wire coming out of that switch and see if the fan turns on, is so, the switch is bad, and they tend to go bad. 12.00 fix, and a good temp fix would be to permanantly ground that switch wire till he could get a repair, yea sure his fan would always run when the car was on, but it would save him overheating. really, and no offense panzer, he took a 15.00 repair at best and made it into a whole mess of re-wiring and repair.

Well thats very true if it was just a matter of a temp switch then really whats the point of all this? $15 and 15 mins and your on your way. Although if it was the circuit problem grounding the relay wont help. At this point there's really no way to know what the problem is with out troubleshooting it.

yea unfortunately i get the feeling from his post everything is ripped apart now, i just finished building the fan harness for my TPI litterally, lol so i kinda know the exact set up on these, and i had a 88 TBI previously, fan switch died on it, man that was the biggest byatch in the world to change, but we're getting off topic, if you want to run this the right way Panzer, you are either going to need to put your old system back together and trouble shoot it, or get a new fan relay and build a new harness for it, running a switch to ground the relay to turn your fan on, but take it from me, using a switch is a bad idea, i forgot a few times and ALMOST over heated the old 88, just nearly caught it each time

Plus these fan motors are not designed to run continuously so you cant even just switch it on and forget it as it will burn itself out and running too cool can cause problems too. Basically its just not a good idea to run it off a switch.

my thoughts exactly, the system needs to be repaired, Any questions you have panzer, i think between rolling thunder I, we can get yah going again

The fan works fine its just the wires getting hot. It rarely overheats anymore because i took out the AC condenser. It rarely touches 220 if the fans working. Which Ive had no problems with for about a week now. I havent been burning switches just wires. Too thin. I want the dual fans because it would be more efficient and Ill need em for the 383 swap in the future. I dont feel like bs'in with relays or the other complicated crap just to keep the thing cool. Corvette's had a switch, why cant I? My stock fan runs slowly but keeps it cool. Ill say this one more time. I had less than 15 minutes to get the fan working or I couldnt get to school. So i had to work quick. It wasnt gonna be permanant. I like things simple, hit the switch and its on till i shut it off.

lol i would certainly hope so between someone how built his own TPI harness and an electronic engineer if we cant figure out how to troubleshoot a simple fan circuit i think we need a new hobby lol.

well you'll need either 2 heavy duty switches for the fans or one switch that will kick two relays, which actually simplifies things, just run ignition power to the ign terminal on each, battery power to the 12v terminal on each, run a ground from your interior switch to the signal terminal on each, then the power leads from the fans to the 12v out terminal on each, then ground your fans to the chassis. flip your switch and both fans will run. hell of alot less wire to run, and easier to trouble shoot later on. and the wires for the fans are 10 gauge stranded core wires, it's entirely how to you how you wish to do it man, its your car. also we understand what you did to make it work, really all you needed to do was ground the signal terminal on your fan relay to get it fired though :/


lol @ the new hobby comment to btw :P

chevy8588, thats the thing I wanna hear. lol. simple, easy to remember. sorry if i was gettin a bit pissy. i had a long day in welding class and todays my 18th bday and I have so much crap to do. Sorry guys.

no prob bro, we all get there, happy b-day, and we're here to help, we've all been there lol.

thanks man Im sure Ill have another problem. That cars my partner in crime, never let me down with almost 200,000 miles on her and still hangin with the best of em. Anyways how should i mount the new fans when i get em?

Here is a pic of my dual fan harness i set up for my l03 converted to LB9, the secondary relay works off of the block switch, and the main one runs off the computer, instead of having two separate relays accross the engine bay, i now have them mounted together for ease of access and troubleshooting later, please excuze the primer on my core support btw, gettin the old girl back up and ready :P

Actually just throwing this out there i think forgoing the relays is still easier (although relays would be better for when you an actual control circuit in place). All you would have to do is run 12V to the fans tie the grounds of the fans together run one heavy gauge wire back to a single heavy 50A automotive switch (like $6 bucks if you know where to shop) and instead of running a heavy ground out back through the firewall back out just ground the other side of the switch to the body inside the the car. Very simple quick and dirty. Again having relays would be nice for later when thell be run off a temp sensor but for now i still think a switch is easier.

as for the dual fans, see if you can find a dual fan TPI in the junk yard, and rip the fans, the mounts and the wiring harness for it, it will make a perfect base for the wiring harness in yours. and thats way all you have to do is bolt the fans straight up

damn man that looks factory. Looks nice and clean too. primer excused. lol what do i have to do about mounting the fans?

yea that would be the quick an dirty way lol, as you can tell from my pictures i try to keep as beautified as possible when my electrical work is concerned, a bit of a perfectionist here :P thank you for the praise BTW, that look is what i was aiming for, anyways the fans mount to a plastic bracket above the radiator, so you MAY be able to make one out of your current upper radiator cover, but you will probably need one off of a dual fan camaro or bird.

amn you answered fasthan i could type. lol

lol sorry :P

well i better get to bed now. Welding tomarrow. Ill be goin to the j yard asap to rip some fans. ill keep yall posted. Thanks for the help guys.

same here, except jury duty instead:P, take it easy guys.

i called the jyard and they said they have a tpi car with the fans and harness still in the car. The motors been grabbed already so i could get it out easier. Hopefully its all in working condition.

should be no issue make sure you pocket the relays too, hey while yer there wanna look for mass airflow sensor for me? ill definitely pay you for it

Sounds like you need a solenoid not a relay for the fan you want to use.
You need heavier wire, you need some solenoids different wire gauges to select from and a multi meter too.
When wireing up fans you can use a solenoid and 12ga or heavier wire and use a multi meter to check voltage drop along the wire to the fan while its running. If you have more than a 1 volt drop on a load or control circuit you are doing it wrong.
What the solenoid will do is allow you to wire up a fan using less than 4 feet of big wire to go from the battery through the fan and to ground and allow you to control the solenoid through thin cheap 18-20ga wire.
Relays and solenoids are always better than wireing up lots of heavy wire. Through big switches.
For 12 inch fans I use standard 2 throw 10amp relays and 14ga wire for the load and 18 or 20ga for the control.
For 16 inch fans I use the same 10 amp relay but always use both sets of contacts to handle the load, 12ga wire and the same control wiring.
For 20 inch plus fans I use a 50 amp solenoid, 10ga wire for most of the circuit (I think 12ga will work if you keep is short) and 18ga wire for the control circuit.

Ill definately check it out for you bro. Ill let you know what I find.