1976 cooling system troubles
Thread Starter
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Joined: Aug 2009
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1976 cooling system troubles
I just replaced water pump, flsuhed system, changed thermostat, hoses. Now car overheats, fan does not come on. It is an electrical fan. I checked all the fuses and they are okay.
Not sure but what should trigger the fan to come on? I changed thermostat thinking I got a bad one.
Any help appreciated.
Not sure but what should trigger the fan to come on? I changed thermostat thinking I got a bad one.
Any help appreciated.
Advanced
Joined: Sep 2008
Posts: 72
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From: Essex
...are you sure the phone didn't ring when you were putting that new t/stat back in, is it possible to put the t/stat the wrong way around? 
If the t/stat is restricting flow the top cooling hose will be cold, whilst the engine coolant is hot....if the fan switch is in the rad and if it's not seeing hot coolant it won't switch in...
...of course if it's impossible to fit the t/stat incorrectly, then suspect anything new
hope this helps
If the t/stat is restricting flow the top cooling hose will be cold, whilst the engine coolant is hot....if the fan switch is in the rad and if it's not seeing hot coolant it won't switch in...
...of course if it's impossible to fit the t/stat incorrectly, then suspect anything new
hope this helps
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
You replaced almost everything, except the radiator. When you drained & replaced the coolant, are you sure you filled up the block ?
If there is an air pocket inside the block and the coolant doesn't reach the thermostat, it won't open and the engine will overheat.
If coolant level is OK, maybe your radiator core is partially clogged...
If there is an air pocket inside the block and the coolant doesn't reach the thermostat, it won't open and the engine will overheat.
If coolant level is OK, maybe your radiator core is partially clogged...
Advanced
Joined: Sep 2008
Posts: 72
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From: Essex
....fan switch?
It is open circuit when cold (switched off) and when a certain temp is reached it closes circuit (switches on) and allows electical curent to flow to power the fan motor...it is no more than a swtich.
I got to tell you that I don't know C3's that well, I have only had two C3's, but I thought all C3's had a mechanical engine driven cooling fan with clutch (viscous fan), so is this an aftermarket fan?
My '79 does has both, mechanical and an electric fan but I always thought the electric fan was for the aircon, to boost flow across the aircon condensor, I could be wrong though?
Ohh, and if the top hose is hot then the t/stat is opening so it shouldn't be that.
If was all 100% fine before you did the work, the rad' won't have just silted up, although be wise to check, you are looking for something else?...Only happens when the car is stopped?
As an aside....we once had a customer do a t/stat on his Jeep Cherokee and he only filled the expansion tank with water thinking that was where all the coolant went, and didn't think to fill the engine cooling system with coolant! He didn't even wonder why it only took 1 litre of coolant
It is open circuit when cold (switched off) and when a certain temp is reached it closes circuit (switches on) and allows electical curent to flow to power the fan motor...it is no more than a swtich.
I got to tell you that I don't know C3's that well, I have only had two C3's, but I thought all C3's had a mechanical engine driven cooling fan with clutch (viscous fan), so is this an aftermarket fan?
My '79 does has both, mechanical and an electric fan but I always thought the electric fan was for the aircon, to boost flow across the aircon condensor, I could be wrong though?
Ohh, and if the top hose is hot then the t/stat is opening so it shouldn't be that.
If was all 100% fine before you did the work, the rad' won't have just silted up, although be wise to check, you are looking for something else?...Only happens when the car is stopped?
As an aside....we once had a customer do a t/stat on his Jeep Cherokee and he only filled the expansion tank with water thinking that was where all the coolant went, and didn't think to fill the engine cooling system with coolant! He didn't even wonder why it only took 1 litre of coolant
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
OK, so what fan(s) are on the car now? Is the mechanical fan still in place? If so your fan clutch might be bad. Is the electical fan a stock unit or an aftermarket (pics would help) if its the stock unit it does not come on until the pass side head gets to 238*, its there to assist in cooling when in traffic or stopped. More stuff to check, look at the radiator to core seals, look at the shroud to dariatoe seals, is the Air Dam in place and not bent out of shape, are the seals to the bottom of the hood there and in good shape.
Thread Starter
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Joined: Aug 2009
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it is an electric fan, I am assuming aftermarket if C3 came with clutch driven. Anyway, I removed the 30 amp fuse / CB at the fuse baox and reinstalled and fan is now working. The haynes manual advises to disconnect neg battery cable when every you do repairs, probably good advise to follow. This is the second time I have done work without following that advise resulting in either a blown inline fuse or CB needing reset.
Thanks for al lthe replies
Thanks for al lthe replies
Intermediate
Joined: Aug 2009
Posts: 28
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73 street race is absolutly correct. Open defroster and turn fan on hi. start car and run@ 2000 rpm until either you feel heat from defroster or engine gets hot. If engine gets hot make sure expansion tank filled w/coolant, and let cool. repeat as nescisary till desired effect
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