guitarguy43113

My vette (stock 1974 l-48 with auto) has an aftermarket electric cooling fan installed on the backside of the radiator. It is a cheapie 16 inch AutoZone special with a manual switch under the steering wheel. No temp sensor at all. PO said the original fan shroud was in the way for a project so it was cut out in several pieces and thrown away. The original cooling fan is still attached to the motor.

Last night I was driving home with the electric fan running and felt something hot against my leg, turns out the positive wire for the manual switch had fallen down against my leg and it was seriously hot. So now I have concerns about the quality of this aftermarket fan and the heat the wiring creates. I see I can order a new fan shroud for around $150 from a few vendors. I would like to just remove the aftermarket fan and either install the correct shroud or go without.

Would this be the best option? How hard would this be? The current radiator is only a few years old and in good shape. Dropping a Dewitts in with the internal fans would be my first choice but is cost prohibitive right now. Anyone run the stock fan and radiator without the shroud? The car seems to never get hot, even without the electric fan on the temp stays below 200 on the center dash gauge.

Thanks.

Mike Ward

Try driving around without using the electric fan and I guess you'll get your answer.

qwank

even with an electric fan, you will still need a fan shroud fro proper cooling. I know from experience.

SteveG75

Two issues here:

1) Lack of shroud will affect cooling at low speed. Above about 35 mph, there is enough natural air flow that the fans are not needed. I have dual Spal electric fans and they never run above about 35 mph.

2) Wiring. Sounds like the previous owner wired the electric fan directly through this switch. The current draw is what is causing the wire to get hot. Electric fans should be wired through a relay that is controlled via a switch (either thermostatic or manual). Power for the fans should come directly from the battery (I use the battery lug on the starter), then fused, then via the relay.

Here is a link to the Spal instructions with good wiring diagrams.
http://www.spalusa.com/pdf/185FH_SPEC.pdf

My $0.02. Get rid of the mechanical fan, get a good set of dual electric fans with built in shroud. Wire appropriately. Enjoy.

guitarguy43113

Thanks for the input, I am pretty sure the current electric fan is going through the fuse box.

How hard is it to remove the mechanical fan? I have never done that before. Adding a quality dual electric fan should easily be within my skill level, and I am currently researching options while on my break at work.

Thanks again.

SteveG75

Mechanical fan is probably held onto the waterpump via studs through the pulley and then nutted. Just remove the nuts, pull the studs and replace with bolts. Should be very easy.

guitarguy43113

Thought I would do a quick update to this thread, I was able to take a few minutes over the weekend and trace the positive cable for the fan to determine where it was attached. Turns out the previous owner wired the positive cable to the back of the radio. So the positive wire from the wiring harness behind the dash is wrapped around the radio positive wire, and then both are wrapped around the fan positive wire. No wonder it gets so hot, I am surprise no fuses were blown when I hit the switch for the fan.

Next project will be to move the cable to the positive wire on the starter.

MrForce

You should still have a relay for the switch...

Rob