has anybody ever replaced their electric fan with a mechanical fan? i have an ongoing electrical issue that i have so far failed to resolve. its a run-ability and drive-ability issue and related directly to the electric fan. i know it usually doesnt make sense to swap a electric fan out for a mechanical one but i have spent a whole summer last year and ton of money replacing parts in an attempt to fix the problem. i am wasting my time if i eleminate the electric fan i can move on. i just want my car to run properly. its a stock 305 TBI. i tried using a fan from a s10 blazer and it doesnt fit properly. i'm willing to take that car to a shop and have it looked at, but i dont want to recieve a several hundred dollar bill and still not have a repair. i was also told i would have to leave it overnight, and i dont like the idea of leaving my car at some shop knowing the owner could possibly take it out for a "joy ride". i dont know if a new fan motor would help. i had changed out the fan that came with the car with a used one off a 84 z28, they both had the same results. could both motor be bad. what usually happens to these fans when they go bad? do they draw too much current or do they fail all together?

 

I had a fan go out on me. The commutator wiped out and caused a massive short along with a fire. What kinds of issues are you having?

 

engine surging, sometimes RPM drops to zero and comes back up, sometimes car will even stall. it doesnt do it all of the time, it comes and goes. it had to unplug the fan switch on the block and low pressure switch from the a/c. now i turn the climate control unit to a/c to run the fan. i watch the temp gauge and turn it on at 210 and off when it cools down. i only run the fan when i have to and i can turn it off and then on again if it acts up. im at the "end of the rope" with this thing. the fan that came with the car did it, i replaced it with a spare fan off of a 1984 camaro, it worked good for a while but now it too acts up. i dont know if its the fan, a ground, or something in the wirring harness. i do know i am fed up with trying to fix it, and i want to get a light-weight mechanical clutch fan and be done with it. it backfired so bad once it allmost blew up the muffler. the muffler is completely out of shape. i dont really care about that too much, because that L03 stock exuast is going to find itself in a dumpster real soon. im going to be getting a performance exuast for my car but can justify spending the money until this is fixed. i dont want to mess up a 800-900 dollar system. so what should i do. replace the fan motor, dont know if this is going to help, send it into a shop and spend several hundred on electrical diagonistics and if they still dont find anything wrong thats a huge waste, or get a mechanical fan and not have to worry about it anymore? did any of the third gens with 305's come with a mechanical fan stock? it would be a whole lot easier to buy a fan, fan shroud, clutch, and fan shaft that was made for the car. i dont like to do things half-assed.

 

The engine surge could be a symptom of having additional load on the engine, or it could be an electrical issue like excessive noise. How does it behave with just the A/C compressor load?

As a test, you could use the min air adjust screw to open the throttle blades up so just the throttle controls the idle and see if the problem still persists.

 

If in fact you have an electrical issue with the fan wiring, rewire the fan thru a new relay and a remote switch and see if the problem goes away. If the problem goes away then swap the switch out for an aftermarket temp sensor that you can mount on the radiator.

Steve

 

I have had the same issues with the electric fans, i went through one because it was continually running when I got the car and then i rewired the fan to a switch in the car so i can turn it on when i needed but the car still ran wamer than i wanted it to, around the 210 mark. So i decided since i was rebuilding the motor and replacing the stock heads with aluminum heads that i wanted to make sure that the car ran cool even in traffic in 100 degree heat, so a replaced the electric fan a flex fan (be carfeul they are really sharp lol) Anyway my point is that you can go to any speed shop and they should have an adapter that will work with the flex fan and i believe there are two different thicknesses for the adapter so you need to figure out which one will work for you. Good luck

 

If you do try out a mechanical fan, double check the rotation. The serpentine systems run the water pump in reverse direction. So a run-of-the-mill mechanical fan won't work.

RBob.