What would be the most common problem besides the fuse, that my fans are not working and thus may be the reason my car is overheating and the solution to it. I have a 1986 Cadillac De Ville 4 Door V 8. I appreciate any help you can give me. Thank You , Sincerly Peggy

Has he replaced the thermostat in the cooling system? That is usually a very common reason for cars overheating.

If the fuse is okay and the bulbs are okay, you have to suspect the 'flasher/indicator' relay which sends the shooting current to a particular bulb

Generic images for an indicator/flasher relay:

indicator relay Google Search

test the motor with a jumper wire from the battery

sounds like it's the switch; but it is important to see whether the fan spins freely or else the switch or resistor block will fail again. the most common reason for these failures is that the motor drags and pulls too many amps, thus overheating the connectors and wires.

Thanks for choosing FixYa and welcome. If you are low on coolant fluid, it will cause it to overheat. Check your coolant fluid level. If your fans are not working or kicking on, it will cause overheating. If so, check the fuse for them. Check for leaking coolant on your lines. A bad radiator can cause overheating and a bad cap can cause overheating. Make sure the cap is snug. Make sure there are no leaks. Now, the most common issue would be a bad thermostat or a sticking thermostat. Next, I would say would be a bad water pump. Now, it could be the water pump valve or impeller, but that is not common. Also, a bad head gasket can cause overheating. Anyone of these can cause your issue. Check fluid first and fans. You may have a leak or a bad fuse. If the fans do not work, that is probably your problem. They should kick on when the car begins to heat up. If the fuse is good and they still don't work, it is either the wiring or the fan itself. I hope this helps you out. Take care. Rick

Thanks for choosing FixYa and welcome. You need to clean the radiator out and also flush the coolant system for 10-15 minutes. You won't get it all out, but it should still run and cool ok. Check your fuse for the fan. If it is good, you either have a bad wire to the fan or a bad fan. For the time being, you can splic the hot wire to the fan, add a wire and hook it to the battery. If the fan works then, you have a bad wire somewhere in that harness. If not, get a new fan. There are other things that can cause overheating besides a down fan. If the fan doesn't fiz the problem, check the thermostat and water pump. The thermostat sticking or going bad is the more common to go bad. It can also be caused by a bad impeller or bad head gasket or coolant cap.

Since you say you changed the thermostat, and that wasn't it then possibly the cooling fan is not functioning properly. Or bad water pump,inaccurate temperature gauge, radiator core blocked or restricted. These are just the most common reasons. Good Luck and I hope this helps a little

Your tempature sensor was probably the reason why your vehicle overheated but as far as hooking the fan to fuse to the motor isnt a bad thing its the same as installing a after market electric fan it will just keep your engine cooler.

1. There are many different reasons that can cause an engine overheat, but they all have in common three aspects. The three aspects which all engine overheat factors have in common are that they cause that the heating system can not get rid of heat, they cause a loss of coolant or they directly cause too much heat in the engine.
2. One first problem which might be the cause of an engine overheat is a problem with the radiator cap and the pressure it holds. If the radiator cap does not hold pressure correctly then coolant could boil and therefore the engine would overheat. Another reason might be caused by thermostat failures; it is recommendable that you check it.
3. The car engine might also overheat due to coolant leaks such as those from the radiator, the hoses, the water pump, the freeze plugs or any others. Also, problems in the water pump could be the cause and therefore you should check it and replace it in case it is needed.
4. Some other reasons by which the car engine could overheat are problems in the exhaust system which you can discover by checking vacuum readings, pipes and converter. Besides, you should also make sure that the radiator hose has not collapsed and the ignition timing is working properly.
5. You should also check the electric cooling fan by making sure that the fan motor, the relay and temperature are correct or otherwise it could cause the engine to overheat. Besides this, you should also check the radiator in case there are any debris in it as well as you should check its hose in case it has collapsed.
6. It is also recommendable that you check the antifreeze concentration which should be 50/50 in order to be correct, otherwise it could cause the car engine to overheat. If you do not find why your engine does overheat, you should ask a mechanic or an expert for advice. You should not try to fix this if you do not have the proper tools and general car knowledge necessary for it.

unplug the fan and run 12 volts direct to the fan from the battery if the fan turns then it is good if not then replace the fan and problem should be solved