Ive got a 91 RS with a 3.1 engine.. Someone who owned the car before me has cut the radiator fan wires. I havent had much time to test and see if it works correctly when its wired up. What are some possible reasons why someone would unhook the wires?

 

So it's got no working fan at all?

Heh in my experience of several 'car guys' I've known, it's cause they don't know what the 'stupid wires' or 'emissions crap' does, and want to 'clean up the engine bay'.

 

Temp controlled separate from stock.
Toggle switch for manual controll.

 

TreeFiddy hit the head right on the nail.

It's because some mouth-breathing knuckle-dragger had a pair of dykes in his hand and even though s/he wasn't smart enough to pass the test for the license to use them, they used them anyway.

Looking at an irrational act like that and trying to assign it a reason, is futile. Never underestimate how stupid a human can be.

Hook em back up and it'll probably work fine. Or at worst, there'll be ONE part somewhere (temp switch connector on the head probably) that's bad and needs replaced.

 

Man I know some people like that haha. Its bad when someone trying to install a radio cuts wires just because theyre there. Or working on the power windows and cutting wires in the trunk :P

The fan works fine. I wired it straight to the battery at first. Then I installed a toggle switch but the wires on it were too small and the switch got hot and broke.
Ill wire it back up the correct way and see what happens when it starts to overheat. I totally forgot to turn the fan on last week after I killed the engine to pump gas. I got 10 miles down the road and just happened to look down at the temp gauge. It was getting up in the red and I said CRAP! Luckily though it cooled down in a hurry once I turned it back on.

Is there any way to test the temp switch without having to heat engine up?

 

If the stock wiring does not work you can run (temporarily)the fan wired to the ignition. Ignition on, fan on ,ignition off ,fan off. You "always" use a relay when your wiring up a switch. You never wire a hot primary directly to a switch. You probably already know this but when you wire a fan , it will spin "pulling air" one way and if you switch the wires around it will "push air"

 

you bet. Dunno why I didnt think of wiring up a relay with it. I figured a simple on/off switch would work.

 

The way to wire a switch into a stock system, is to just put it in parallel with the fan switch in the head... that way, it works the stock relay just like the stock fan switch does, and only carries the relay coil current, which is only a couple of % or so of the fan current. A tenth of an amp MAYBE, instead of the 30 - 50 amps that the fan motor draws.

Not sure why it's ever a good idea to bother with a switch AT ALL in the first place; but just from a technical point of view, leaving the "rightness" aside, that's the right way to do it.

To test the switch, put it in a pan of boiling water on the stove, with a thermometer in the water and your DMM hooked to it. Or, even easier, just go to the store and buy a new one... they don't cost much more than a pan full of water anyway.

 

Thanks for the info. This car is a project in progress. I'm gonna give it a nice makover. From the way it sounds, I dont think its ever had a tuneup. It has a slight miss when its idling and that's gonna be my next step. A fresh paint job and new window tint are all in store. Im hoping everything I need to know is on this forum. Im sure all the information is here. Im 100% positive it is with all the contributors I see. =]