Technical 5 Pin Relay burn & melt in Fiat Uno 1.7 Diesel (air-conditioning help please)

[vkdc]

Hi,

I have Fiat uno Diesel 1.7, While driving with AC system ON, I hv fault in my car that the engine temperature raise above the 80 degree celcius.
And when i stopped car to inventigate this, I sow the Raditor fan is moving even i switch off the ignition.
While inspecting the Replay box I found that the 5 terminal relay has got burn out and melted (12V 30 Amp 5 Pin Relay SPCO 30A).
Temporary repair has been done by nearest machenic by cutting the wires & replacing with 4 terminal relay and some jumpers.
With this temporary connections Raditor Fan get switched-on along with AC condenser fan and radiator fan moves slowly. eventually engine temp won't goes down.
In case of AC switch-off radiator fan movesd in good speed.

Now i hv got the exact five pin replay along with socket for replacment.
Can any one guide me how to make the connections as orginally.I mean
which colour of wire would be connecting to which terminal of replay.

Thanks in advance.

Best regards,
VKDC

 

[Ucof]

re: 5 Pin Relay burn & melt in Fiat Uno 1.7 Diesel (air-conditioning help please)

And when i stopped car to inventigate this, I sow the Raditor fan is moving even i switch off the ignition.

This is meant to happen.

Other than that, I have no idea about the wiring.
Someone will be along shortly to answer you.

Please help yourself to tea, coffee or individually wrapped mints.

 

[EssexUno]

re: 5 Pin Relay burn & melt in Fiat Uno 1.7 Diesel (air-conditioning help please)

Please help yourself to tea, coffee or individually wrapped mints.

Lol this is exactly what i think of he forum always someone along to help you when in need

Sorry i can't help with the relay, I only have a 1.0 i.e. so no AC for me lol

 

[alexGS]

Hello VKDC - welcome to the forum

Unfortunately it might be a while before we find someone who can check their air-conditioning relay wiring for you - it has to be someone in India, because in the UK (and NZ for that matter), the Uno did not come with A/C.

On the face of it, the 'temporary repair' sounds OK to me; in A/C systems generally, the fan should run at a slow speed when the A/C is on, and then run at a fast speed when the A/C pressure switch activates (system pressure is higher than normal) OR when the engine cooling radiator switch closes (the same as for non-A/C cars).

Therefore I suggest you check that when the engine cooling radiator switch contacts close, the fan should run at full speed. You can find the radiator switch screwed into the radiator, usually near the bottom and on the left-hand side of the car (as you face forward from the driver's seat). Unplug the switch and bridge the plug terminals using something like a paper clip. As Ucof says, this will normally run the fan even if the ignition switch is off - but the important thing is that the fan should run at full speed.

If anyone has an A/C-equipped Uno, please add your wiring details...

Cheers,
-Alex

 

[vkdc]

Hi,
Thanks guys for your all possible solutions.

I have come back to my original Relay ( 5- terminal).
Now the current scenario is whenever I switch-ON the A/C system switch
the REaditor FAN and condensor fan both start moving. However, the Raditor fan moves slowly.
As per car-Electrician Raditor & condensor both will spin together and speed of radiator fan switch to fast as soon as the temperature of engine raise over the certain degree celcius.
In normal condition when A/c is off, Raditor fan moves on temperature condition and got off after few minutes.

This car is Fiat Uno 1.7 Diesel model from India with A/c and power steering.

I need your experts comment on above condition, whether this configuration is perfect or functioning is right what it should be?

Hope to hear you on this!

Cheers...

Reg.
VKDC

 

[Harish602]

Hi VKDC,

I too have a UNO 1.7D in Mumbai but my radiator fan runs at full speed when the temperature crosses somewhere around 85 deg otherwise its off. When the fan switches on the temprature falls to almost 70 deg and again the fan switches off and it switches on & off between these readings. I am not sure whether it should behave this way.

Hi,
Thanks guys for your all possible solutions.

I have come back to my original Relay ( 5- terminal).
Now the current scenario is whenever I switch-ON the A/C system switch
the REaditor FAN and condensor fan both start moving. However, the Raditor fan moves slowly.
As per car-Electrician Raditor & condensor both will spin together and speed of radiator fan switch to fast as soon as the temperature of engine raise over the certain degree celcius.
In normal condition when A/c is off, Raditor fan moves on temperature condition and got off after few minutes.

This car is Fiat Uno 1.7 Diesel model from India with A/c and power steering.

I need your experts comment on above condition, whether this configuration is perfect or functioning is right what it should be?

Hope to hear you on this!

Cheers...

Reg.
VKDC

 

[a73uk]

We didnt get AC equipped Uno`s in the UK, but usually on basic AC equipped cars, the fan will operate constantly (at high speed) as soon as the AC is switched on.

I`d imagine in a hot country, this would go for all AC equipped cars.

If theres an air lock in the radiator (round the sensor pickup) it can cause the fan to not cut in or cut in very late.

Have you tried putting a wire between the battery & relay? there could be more bad wiring somewhere, in fact if the relay burnt out like that there could be a bad earth or switch.

Have you thought about putting a secondary relay with a manual dash mounted switch?