Rad fan not coming on

Maintenance advice to keep your Spider in shape.
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Rad fan not coming on

Post by davery »

RRoller123 wrote:Just an idea... It is possible that the car was configured with a manual overide switch, as many POs did in the past when unable to resolve fan cooling problems. Mine came with this. If you see a small switch typically somewhere under the dash, driver's side, near the fuse box, that may indicate what is going on. After resolving the thermoswitch, burping, gauge sensors, and wiring problems( :shock: ) I just left the overide in place, properly wired as a backup.
I have had the car 17 years and have not noticed anything such as this. As I was looking at the fan switch I noticed the wire going into it was a bit frayed. I trimmed it back and grounded it and the fan came on. Then I spliced another peice of wire in and the fan will not come on. I guess I should run it and feel if the bottom of the rad is getting hot and rule that out. Thanks for all the input.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Rad fan not coming on

Post by davery »

davery wrote:
RRoller123 wrote:Just an idea... It is possible that the car was configured with a manual overide switch, as many POs did in the past when unable to resolve fan cooling problems. Mine came with this. If you see a small switch typically somewhere under the dash, driver's side, near the fuse box, that may indicate what is going on. After resolving the thermoswitch, burping, gauge sensors, and wiring problems( :shock: ) I just left the overide in place, properly wired as a backup.
I have had the car 17 years and have not noticed anything such as this. As I was looking at the fan switch I noticed the wire going into it was a bit frayed. I trimmed it back and grounded it and the fan came on. Then I spliced another peice of wire in and the fan will not come on. I guess I should run it and feel if the bottom of the rad is getting hot and rule that out. Thanks for all the input.

Radiator is hot at the bottom. I also found what the brown/white wire is that I found behind the fuse box. It is to the clock. I guess the only reason the fan does not come on would be the switch?
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
So Cal Mark

Re: Rad fan not coming on

Post by So Cal Mark »

if you remove the two wires from the switch and connect them together the fan should run. That tests the entire system without the switch. Then either the switch has failed or it's not getting hot enough to close the switch. Do you have access to an infrared thermometer to test the temp at the bottom of the radiator. I've some with enough crud buildup to insulate the switch
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Rad fan not coming on

Post by davery »

So Cal Mark wrote:if you remove the two wires from the switch and connect them together the fan should run. That tests the entire system without the switch. Then either the switch has failed or it's not getting hot enough to close the switch. Do you have access to an infrared thermometer to test the temp at the bottom of the radiator. I've some with enough crud buildup to insulate the switch

I willl look at that.
Last edited by davery on Sun Mar 17, 2013 1:57 pm, edited 1 time in total.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Rad fan not coming on

Post by davery »

So Cal Mark wrote:if you remove the two wires from the switch and connect them together the fan should run. That tests the entire system without the switch. Then either the switch has failed or it's not getting hot enough to close the switch. Do you have access to an infrared thermometer to test the temp at the bottom of the radiator. I've some with enough crud buildup to insulate the switch
No gunk on the switch. I found a new switch locally and am going to pick up today. The switch comes with a pigtail connection. I had to cut the one off of the car, as it would not seperate. I know these type of connectors are not common, anyone know what they are called? They do not have any at the place I found the switch. Thanks.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
redcars
Patron 2020
Patron 2020
Posts: 487
Joined: Sat Jul 31, 2010 9:36 pm
Your car is a: 1981 Spider 2000
Location: Collinsville, IL

Re: Rad fan not coming on

Post by redcars »

I call them bullet connectors, but am not sure if that is the correct terminology. When in doubt I look in McMaster-Carr they have about everthing.
1987 Lotus Super 7 clone
1981 Fiat Spider 2000 AT
1982 Fiat Spider 2000 5sd
1970 Fiat Coupe
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