I just bought an 86 vert, my first vette - YAY! The guy I bought it from (kind of a butcher) put a manual switch in to control the main cooling fan on the in side of the radiator. The first switch went bad and I replaced it with another identical switch. After a while, the second switch melted after being on for a while (not that long) and destroyed the switch and melted the jacket on the connecting wires. It was a three wire switch (1 hot, 1 feed to the fan and 1 ground wire) the hot and feed melted. Does anybody have any ideas why this is happening? Is there too much resistance or something else. Thank you for your help!
Michael :confused: :banghead: :flag

PS I am considering going to an automatic, thermostat controled switch.


[Modified by MDGaumond, 2:09 PM 12/10/2003]

 

Hard to tell how that is wired without seeing it or a schematic. but your setup sounds incorrect to me.
I would use the exsisting fan relay circuit and just add a switch to ground to activate the relay. All the information on the wiring can be found in a Helm manual for your vehicle (A highly recommended manual if you plan to do your own repairs).

 

I've seen a number of these "fan bypass" butcher jobs. I've chased may "other" problems back to the buther job.
I've never seen these heat problems commonly refered to. That said,....
I'd strongly suggest going back to the stock setup. That will get you outta trouble the fastest. (Don't forget to clean the leaves outta the condenser/radiator gap.)
W/ the PWR/GND,... I'll guess the switch is illuminated (lights up). As I recall, power comes from the battery to the fan relay, to the fan, then to GND. The ECM controls the relay. The proper way to add a switch to turn the fan ON, would be to add a switch to the ECM side of the ckt. ECM side of RLY control line is either switched to GND or left open. (2 wires). If the butcher added a switch to supply power directly to the fan,... it is melting because it can't handle the current drawn by the fan. That is why the relay is there. What does the switch say: 12V 15A ???? (That is a beefy switch.)
Not seeing your circuit,... I can only guess how it was butchered.
Bottom line is,... melting because it is doing something outside of it's designed voltage/current.


[Modified by ZylaRace, 6:02 PM 12/10/2003]

 

:iagree:
Sounds like to much current :eek:
Your manual switch should be controlling ground to the relay.
:cheers: