tfuith

thanks for reading. i have a 62 fuelie . when i bought it had a aux electric fan installed, in addition to the regular fan. it also has a 1 wire alternator that looks like a gen. when i start the car without the aux fan on it shows a slight discharge on the gage, but when i switch on the aux fan it shows total discharge on the gage and the engine does not run as good as before i turned it on, wont hold an idle.

the car runs hot without the aux fan around 220 with a160 stat or without once i engage the aux fan it drops to a little under 180. this is with or without a stat. i am lost for solutions. i keep a battery tender on it always

any suggestions appreciated

tom f.

bknd

Sounds like your alternator is bad. Your battery gauge should go from about 12 volts before you start the car to 15+ volts with it running and the alternator functioning properly. Electric fans do draw some juice but any properly functioning alternator shouldn't have a problem. You also need to check out your cooling system. That extra fan is just a band aid. Check your coolant level (car cold of course), make sure your coolant is clean, and the radiator isn't corroded. The water pump is hard to check, but if you take your belt off it should spin smoothly. A high volume water pump may help your situation. My goal if it were my car would be to get it running properly without using two fans. I'd keep one or the other, but you would want the electric one to switch on at a set temp and not with a switch as you stated. Lots of great advice on this forum, if you continue having issues just report back and I know someone will be able to help you. Good luck!

AZDoug

One wire alternators aren't the best choice for use with high draw accessories at idle speed.

The stock cooling fan , if the fan clutch is good, should be sufficient to cool your car at idle.

Also, any high draw item should NOT be getting its juice across the amp gauge. Make sure you use a relay, and that the relay power is direct from the battery

Doug

plaidside

First I would check to make sure you have battery voltage at the terminal of the generator/alternator with the engine off.
If you have battery voltage then check it again when the car is running around 1200 RPM.
If the voltage is now above 15 then you have a wiring problem, if the voltage is below 12 then the generator/alternator is not working.
Joe

tfuith

joe, i am taking it to the chevy dealer i trade at.

i did as you said and found over 15 @2300 rpms

thanks for the help

tom f.

HilltopClassicCars

Tom, I agree with the first three replies above and can relate a similar experience. First I would inquire how you are determining the car is running hot, you didn't say it was overheating, just running hot. Are you using the temp gauge on the dash or some diagnostic test equipment to make the determination it's running hot?

My experience is that one year ago I purchased a 60 for my wife, it had been Bubba'd and neglected in a number of ways and areas. It had a stainless steel direct drive flex fan and an electric fan. The generator had been replaced with a three wire internally regulated alternator. This was done not for the electric fan, but because power steering had been added and they located the power steering pump where the generator would normally be positioned.

I confident the electric fan and SS flex fan were not necessary. The dash temp gauge didn't operate when we got the car, that ended up being a temp bad sending unit. A new sending unit caused the dash temp gauge to indicate the engine was running hot enough that it should have been overheating and puking coolant which it didn't but that's another story.

I did some tests with accurate test equipment and found though the dash temp gauge indicated it was running hot, it really wasn't. I removed the SS flex fan and the electric fan and put the correct mechanical clutch fan in their place. It still didn't and doesn't run hot and looks so much better under the hood now. I believe Bubba used the dash temp gauge as a reason to install the SS flex fan and electric fan and "fixed" a problem that didn't really exist.

If the cooling passages in the block and the radiator are clean, a mechanical clutch fan properly located in the correct and properly mounted shroud should be able to keep the engine from running hot. That is of course assuming the engine doesn't have any issues that would contribute to running hot (retarded ignition timing, lean fuel mixture, vacuum leaks, etc). BTW, I forgot to mention my wife's 60 came with a NOM 350 rather than a 283 and the mechanical clutch fan still has no trouble keeping it from running hot.

Hope this helps you find the real cause and solution to your situation.