Radiator Fan not Working. fan works, new swith and therm

[sjwcougs]

I have had some recent problems with the cooling system. After sitting for a while the radiator fan has quit working. I tested the thermostat and it didn't seem to be opening properly so I replaced that and while the cooling system was drained I decided to replace the fan switch as well. The fan workes fine as I have tested it without the fan swith by jumping the leads on the wiring.

I replaced everything and I'm still not getting a fan on at slightly over 190 on the temp gauge. Lower radiator hose seems to be getting nice and warm so I believe the thermostat is working properly. I had to make a longer lead for the fan switch because for some reason whoever manufactures this switch for IAP made one wire shorter and it won't reach the plug. I tested my lead by using it to jump the leads to the switch to turn on the fan. Maybe a faulty fan switch? I guess that will be my next test. Ideas?

[Danno]

Wouldn't be the first fan switch that was faulty when new. Were you sure the old one was bad? Basically, if your fan works when jumped and the radiator is getting warm, then it's either that switch or a weird clog that is blocking warm fluids from getting to the switch. I'd go with switch first.

[Danno]

oh, and I suppose it could always be a bad water pump, but start with simplest.

[Danno]

lol, I'm back. What about air in the system?

<edit> one more, just read a similar situation on another forum, they suggested checking fuses.

[sjwcougs]

Is there a fuse for the fan switch? The fan works and therefore that fuse is fine. It either has to be a clog so the coolant is not getting to the switch in the radiator or a faulty switch. I'm not 100% sure the old switch was bad. I just replaced it since I was draining the the system anyway to replace the thermostat. I thought it was worth the 15 bucks to just take care of it. I will test both switches to see if they created a closed circuit at temp. I should be able to do this in a pot of hot water and a multimiter I would think.

[mbouse]

according to the Spider experts i have conversed with over the years, the two most changed items that never really needed changing are the T-stat and the rad fan switch.

1. the most likely culprit for ANY Fiat electrical failure is a failed ground. Always suspect the ground until you prove otherwise
2. the second most likely culprit for this particular circuit is the fuse. I believe the only unfused circuit is the starter.
3. be sure to triple check that t-stat to ensure that you put it on properly. three hoses and three fittings are quite easily put in the wrong orientation. get it wrong, and it won't work.
4. in your spider, the highest point in the cooling system is NOT the radiator neck. therefore, air is near always trapped when you drain and refill the system. getting the air bubbles out is a technique that we all must learn.

[So Cal Mark]

On an FI car I use the throttle body heater hose to top off the system and bleed the air out, or add a flush tee to the heater hose that loops over the cam cover. If the lower rad hose and radiator is getting hot, then the t-stat is opening. If you can jump across the fan switch and make the fan run, then the fuse and ground are good

[pope]

Dont you just love how Fiat used bottle caps for the grounding of the engine wires. I unscrewed on once and turned it over and it said Dr.Pepper on mine. LOL Also, No deposit, no return. I wasnt sure if they meant the car or the cap.

[sjwcougs]

Ok guys I've already checked that the fan does indeed work with the leads jumped. that means the fuse is ok and the fan works. The lower radiator does get warm so T-stat is working properly. New fan switch installed as well.

[Danno]

if you're sure the air is bled out, then it just has to be the switch....

[mdrburchette]

Swap the new switch for the old one since you're not sure the original was faulty. Have you tried letting it heat up a bit more? The gauge may not be reading true and the fan may come on after the 190 mark. Do you know when the thermostat fully opens up? If you have an air bubble in the cooling system, the gauge will usually peg to hot about the time the fan should come on, scaring the daylights out of any gauge watcher. Another thing to check is if the wires to the switch and fan go to a relay on the left fender. I don't know what year your car is, but my 72 has the switch and fan going to the relay that is wired straight to the "L" fuse. If you are bypassing the relay and switch when you checked your fan, that doesn't necessarily mean the fuse is good because you are, in effect, taking the fuse out of the loop. Good luck with your problem!

[sjwcougs]

Well, problem solved. I may have been a little quick to jump to conclusions. Up until now I had not road tested her. I just let her idle up to temp. I took her out for a spin couldn't get her up to 190 until I stopped in the driveway and idled at 2000 until the temp gauge went over the 0 in the 190 marker and than kicked in while in the driveway. Is that about right?

At what spot on the gauge should you get truly worried about engine damage?

I'm going to back flush the system now using the prestone easy flush T kit that somebody else had previously installed. Any experience with this product? I just have water in the system right now because I ran some prestone complete flush through the system prior.

One more thing. There is a lot of exaust smell and I'm sorry that isn't much of a diagnosis or description, but it stinks. Running rich? Causes? Sorry to overwhelm everyone with Qs.

What kind of gas mileage should be expected? Last summer I was only getting about 20 ish MPG. Sometimes a little higher, but that seems like high consumption for a 2 litre engine.

[Danno]

I can't answer with 100% confidence, but i'd guess that should be ok. Like Denise(?) said, your guage could be off by a few degrees. sounds like things are working OK, imo.

[rlux4]

Being an '82, my 2000 is fuel injected. I'm getting a pretty consistent 27-28 mpg. I never hot rod the car, pretty much drive it like an old man, which makes sense, me being one and all.

[manoa matt]

The "T" fitting should be installed in the heater hose that leads to the fitting on the cylinder head. It's great for flushing and back flushing, and will greatly ease getting air out of the system as it is now the highest "open" part of the system.

Running stright water will run a few degrees cooler than 50/50 mix because the water has less surface tension than anti-freeze.

My fan typically comes on between the 1 and the 9 of 190, but the temp senders and gauges are not entirely accurate. The temp at which your specific engine runs depends on several factors ie, water pump impeller condition, thermostat temperature rating and condition, fan switch temperature rating, cylinder head and block flow and cleanlieness.

Probably the bigest factor of opperating temperatures would be the condition of your radiatior. Before I had my radiatior re-cored with a 3 row high efficiency the car ran a few deg hotter than it currently runs.

I had intermittent problems with my fan not comming on and it turned out to be a bad ground connection at the ground pod (bottle cap).

Matt