*Wiring temp sender to kick fan in?*

[Gtedger]

2003 Fiesta 1.25: had problems with the fiesta overheating even though temp gauge says normal temp on dashboard. After box ticking all the usual culprits (relays, fuses, isolating fan to test it works which it does etc) found out it's the ECU ignoring any messages from the temperature sensor. Decided to bypass the ECU by cutting through the top radiator hose and fitting an aftermarket inline sensor adapter and temperature gauge with sensor. Has anybody fitted one of these so that it works the aftermarket gauge as well as kicking the fan in when the engine starts to overheat. Please could you give me some advice as there are no instructions or wiring diagrams and electrics aren't my thing or if anyone knows of any YouTube videos that are actually useful that would also be appreciated. Thanks.

[Gizza11]

I fitted one of these back in the  very early eighties on a Ford Capri that I fitted a 2ltr engine to. It worked 100% and I fitted a bypass switch so that the fan would come on when I wanted by the switch. The reason was that the old engine had an old style viscose fan assy. not an electronic sensor type and this new sensor would save power from the engine by not running a fan all the time. your new system will work fine on yours and the engine will not overheat anymore unless you have other problems. I would as a precaution completely flush the radiator and system as well with a good 2 or three pack cleaner and add new fluid and anti freeze as that may help a bit too (you will be surprised at how mucky it can get even in a short time). Unfortunately I cant help with the wiring as this will depend on the exact kit you have but I am sure some one can. The only thing is (I'm not sure on this) does a modern car  computer need the temp senders signal to set parameters for the fueling system among other things this would be worth looking into. Of course your new system may have a confection to the gauge for this.

[Gtedger]

Okay I will try it. Thanks.

[Lenny]

1 hour ago, Gtedger said:

Okay I will try it. Thanks.

Hi,

I can help you with wiring the gaugecand sensor I can also show you how to make the backlight of the gauge dim along with the other dash lights when you turn on your dipped beam at night as the aftermarket gauges can be quite blinding.

can you link the kit you purchased or show me some pictures please. 

 

[Gtedger]

15 hours ago, Lenny said:

Hi,

I can help you with wiring the gaugecand sensor I can also show you how to make the backlight of the gauge dim along with the other dash lights when you turn on your dipped beam at night as the aftermarket gauges can be quite blinding.

can you link the kit you purchased or show me some pictures please. 

 

Hi Lenny, the link of the exact one is this one:

https://www.ebay.co.uk/itm/152374093059 

Thanks

[Gtedger]

2 minutes ago, Gtedger said:

Hi Lenny, the link of the exact one is this one:

https://www.ebay.co.uk/itm/152374093059 

Thanks

I think there's a problem with the link, I have instead attached a few pictures.

[Lenny]

2 hours ago, Gtedger said:

I think there's a problem with the link, I have instead attached a few pictures.

Thanks mate,

Two of the cables; most likely the red and the black are positive and negative cables,

You should splice red to an ignition positive feed within the car, probably easiest to use a "piggyback fuse adaptor" and put it in to a fuse which becomes live when the engine is running.

The green cable then is a sensor feed, it connects to the white cable on the temperature probe, 

The black cable on the temperature probe then connects to the hose adaptor you have fitted in the engine bay.

then run a cable from the pipe adaptor to the body of the car to earth it. 

I've done all this on my first car.

Best to purchase cable from this seller: http://stores.ebay.co.uk/AutoStar-Shop 

Also get a cable crimp tool and some insulated spade connectors 

 

[Lenny]

You were saying you have the temp sensor fitted already in the top hose and it triggers the fan.

so all you need to do with the gauge is connect the green cable to the white cable of the temperature probe.

and power the gauge to an ignition live feed and an earth feed. 

It will then display temp. 

[Gtedger]

Hi Lenny

Thanks for your help up to now.

Just want to clarify something- I haven't fitted the inline temperature adapter or temperature probe. This is something that I intend to do so that I can completely bypass the engine's ECU which is causing the problem. I cannot link to any of the original temperature sensor cables on the car.

The temperature probe that came with the adapter only has a connection for one cable, which would be the green sensor cable from the new clock, and a screwpoint on the adapter housing for an earth to be fitted from there to the body. 

I cannot connect to the white wire of my original sensors as I have to bypass all of this to bypass the ECU. You have indicated that the green cable connects to the white cable (which I cannot do, so this cable will go directly to the new temperature sensor) and the black cable connects to the body of the hose adapter in the engine bay.

Therefore I'm thinking i have to put the green wire from the clock onto the sensor, the black wire from the clock onto the body of the sensor adaptor where the earth fits, and another cable from this point onto the body to complete the earth for the clock and the sensor. Could you let me know if this is correct?

If this is correct, at least I know I will be okay for wiring the clock in. My next problem is how do I connect the new sensor directly to the fan with its own independent power, so that when the new sensor reaches the appropriate temperature, the fan will kick in to cool the engine? I'm wondering if I've ordered the wrong temperature sensor because the one I have has only one connection for the green wire, but no other connections from the sensor to the fan. Do I need to order another sensor with a two spade connection point?

Thanks in advance,

[Lenny]

1 hour ago, Gtedger said:

Hi Lenny

Thanks for your help up to now.

Just want to clarify something- I haven't fitted the inline temperature adapter or temperature probe. This is something that I intend to do so that I can completely bypass the engine's ECU which is causing the problem. I cannot link to any of the original temperature sensor cables on the car.

The temperature probe that came with the adapter only has a connection for one cable, which would be the green sensor cable from the new clock, and a screwpoint on the adapter housing for an earth to be fitted from there to the body. 

I cannot connect to the white wire of my original sensors as I have to bypass all of this to bypass the ECU. You have indicated that the green cable connects to the white cable (which I cannot do, so this cable will go directly to the new temperature sensor) and the black cable connects to the body of the hose adapter in the engine bay.

Therefore I'm thinking i have to put the green wire from the clock onto the sensor, the black wire from the clock onto the body of the sensor adaptor where the earth fits, and another cable from this point onto the body to complete the earth for the clock and the sensor. Could you let me know if this is correct?

If this is correct, at least I know I will be okay for wiring the clock in. My next problem is how do I connect the new sensor directly to the fan with its own independent power, so that when the new sensor reaches the appropriate temperature, the fan will kick in to cool the engine? I'm wondering if I've ordered the wrong temperature sensor because the one I have has only one connection for the green wire, but no other connections from the sensor to the fan. Do I need to order another sensor with a two spade connection point?

Thanks in advance,

You have explained everything correct there mate,

The older version of the temperature probes had a black and a white cable on them and the black was an earth which could be ring terminal and connected to the screw on the aluminium adaptor then earthed to the body of the car; that is what I was originally referring to as I don't know anything atall about the specific stock wiring system within your vehicle.

from the sounds of it; your new temperature probe that came with the gauge has an earth built inside connected to the casing of the probe itself; which makes sence when its connected or screwed in to the aluminium hose pipe adaptor. 

You have the plan 100% correct there for wiring the gauge, you will need to measure the internal diameter of the radiator hose in order to purchase the correct sized alluminium adaptor.

and in order to have the fan automatically switch on at a set temperature you would need to fit a relay type unit which would either connect to the new temperature probe along with the gauge, or it will have its own separate probe.

a relay is an automatic switch it operates much to say "if you do this, I'm going to do that" 

The relay would take in power from a fused ignition live feed the same one as the gauge and the relay would sence the temperature from the radiator aswell as connecting power directly to the existing fan, which will bypass all original wiring and sensors when connected.

When a pre determined temperature is achieved within the radiator the relay will then switch on the fan to regulate temp until it drops below its limit.

Now; The temperature probe you have with the gauge there; they will read out real time temperature more accurately than the stock unit but they don't have any relay built in or anything to alter the state of the temperature itself there just capable of monitoring the current status.

in my opinion there a good addition to an aftermarket setup but there not the vital part.

I'm not sure how much a thermostat system will cost but in the mean time you could fit a manual switch between the fan and an ignition live feed to allow you to switch on the fan yourself when the temperature reached around 200 degrees Celsius 

Here's the sort of kit you would require for that but again; I DON'T KNOW YOUR EXACT VEHICLE SPECIFICATIONS AND I DON'T REFER TO THEM, I ONLY KNOW AFTERMARKET UNIVERSAL ITEMS the temperature probe size for your engine maybe a different diameter however you could try it using the stock temperature probe.

Link: http://www.ebay.co.uk/itm/185-170-Degree-Electric-Cooling-Fan-Wiring-Install-Relay-Kit-Thermostat-NEW-K8Z9-/292069240854?hash=item4400aef016%3Ag%3AMjQAAOSwYXVY0zDA&_trkparms=pageci%3Add34b0cb-22cc-11e7-9c81-74dbd180683c%7Cparentrq%3A77e11e0715b0aa411d5fcb6dffff2829%7Ciid%3A28 

[Gtedger]

On 16/04/2017 at 6:45 PM, Lenny said:

You have explained everything correct there mate,

The older version of the temperature probes had a black and a white cable on them and the black was an earth which could be ring terminal and connected to the screw on the aluminium adaptor then earthed to the body of the car; that is what I was originally referring to as I don't know anything atall about the specific stock wiring system within your vehicle.

from the sounds of it; your new temperature probe that came with the gauge has an earth built inside connected to the casing of the probe itself; which makes sence when its connected or screwed in to the aluminium hose pipe adaptor. 

You have the plan 100% correct there for wiring the gauge, you will need to measure the internal diameter of the radiator hose in order to purchase the correct sized alluminium adaptor.

and in order to have the fan automatically switch on at a set temperature you would need to fit a relay type unit which would either connect to the new temperature probe along with the gauge, or it will have its own separate probe.

a relay is an automatic switch it operates much to say "if you do this, I'm going to do that" 

The relay would take in power from a fused ignition live feed the same one as the gauge and the relay would sence the temperature from the radiator aswell as connecting power directly to the existing fan, which will bypass all original wiring and sensors when connected.

When a pre determined temperature is achieved within the radiator the relay will then switch on the fan to regulate temp until it drops below its limit.

Now; The temperature probe you have with the gauge there; they will read out real time temperature more accurately than the stock unit but they don't have any relay built in or anything to alter the state of the temperature itself there just capable of monitoring the current status.

in my opinion there a good addition to an aftermarket setup but there not the vital part.

I'm not sure how much a thermostat system will cost but in the mean time you could fit a manual switch between the fan and an ignition live feed to allow you to switch on the fan yourself when the temperature reached around 200 degrees Celsius 

Here's the sort of kit you would require for that but again; I DON'T KNOW YOUR EXACT VEHICLE SPECIFICATIONS AND I DON'T REFER TO THEM, I ONLY KNOW AFTERMARKET UNIVERSAL ITEMS the temperature probe size for your engine maybe a different diameter however you could try it using the stock temperature probe.

Link: http://www.ebay.co.uk/itm/185-170-Degree-Electric-Cooling-Fan-Wiring-Install-Relay-Kit-Thermostat-NEW-K8Z9-/292069240854?hash=item4400aef016%3Ag%3AMjQAAOSwYXVY0zDA&_trkparms=pageci%3Add34b0cb-22cc-11e7-9c81-74dbd180683c%7Cparentrq%3A77e11e0715b0aa411d5fcb6dffff2829%7Ciid%3A28 

Hi Lenny, thanks very much for your help so far. Gave it some thought as to what you said about fitting a switch direct to the fan, but i cant really rely on my daughter remembering to switch the fan on and off to cool the engine by which time if she forgets she will end up cooking the engine.

In picture 1 I'm thinking of using the new ford sensor i fitted when the problem occured where the screwdriver points to, i have taken the plug off the new sensor and put it onto the old sensor.

I have to do this to stop the temperature gauge flashing on the dashboard and also to put the engine management light out and leave this connected up out the way as it seems to keep the engine management happy.

I am going to go to a local breakers yard tomorrow and will cut a piece of cable off another fiesta which will have the appropriate plug for the sensor, and plug that onto the new sensor which will have the proper colour coded wires which is a brown and a white one. While I'm out I'll also purchase a piggyback fuse adapter and a relay.

In picture 4 is a standard fiesta relay, is this the type i will need? To be honest i have no idea how to wire into and out of a relay, would you be able to tell me what wires go to what spade on the relay? I will have the brown and white wire off the sensor, a live wire from the piggyback and i will need to know how to wire them from the relay to the fan. The fan wires are shown on the fan plug in picture 3. 

Then fingers crossed this will cure the problem!

Many thanks for your help mate.

P.s. i forgot to mention, i don't know why but the spades on the relay are numbered up in tiny numbers in the order of 1, 2, 3 & 5. Don't know if this is of any use or would i need a totally different type of relay.

[Lenny]

21 hours ago, Gtedger said:

Hi Lenny, thanks very much for your help so far. Gave it some thought as to what you said about fitting a switch direct to the fan, but i cant really rely on my daughter remembering to switch the fan on and off to cool the engine by which time if she forgets she will end up cooking the engine.

In picture 1 I'm thinking of using the new ford sensor i fitted when the problem occured where the screwdriver points to, i have taken the plug off the new sensor and put it onto the old sensor.

I have to do this to stop the temperature gauge flashing on the dashboard and also to put the engine management light out and leave this connected up out the way as it seems to keep the engine management happy.

I am going to go to a local breakers yard tomorrow and will cut a piece of cable off another fiesta which will have the appropriate plug for the sensor, and plug that onto the new sensor which will have the proper colour coded wires which is a brown and a white one. While I'm out I'll also purchase a piggyback fuse adapter and a relay.

In picture 4 is a standard fiesta relay, is this the type i will need? To be honest i have no idea how to wire into and out of a relay, would you be able to tell me what wires go to what spade on the relay? I will have the brown and white wire off the sensor, a live wire from the piggyback and i will need to know how to wire them from the relay to the fan. The fan wires are shown on the fan plug in picture 3. 

Then fingers crossed this will cure the problem!

Many thanks for your help mate.

P.s. i forgot to mention, i don't know why but the spades on the relay are numbered up in tiny numbers in the order of 1, 2, 3 & 5. Don't know if this is of any use or would i need a totally different type of relay.

I understand that you need to remove the original temperature sensor and tape it up somewhere out of the way in order to keep the ecu happy,

The easiest option for installing the new system would be to purchase this kit from eBay which comes with fitting instructions http://www.ebay.co.uk/itm/292069240854 

if you can measure the thread diameter of the temperature sensor you have; you will then know the size required from the eBay seller I've linked you to there.

The easiest way to find out the size would be to bring the sensor to somewhere like B&Q where they have a range of nuts and bolts in little drawers, 

Search through the nut sizes until you find the size that takes the sensor; you then know the diameter of the sensor and you can contact the eBay seller linked above to purchase the kit containing the correct sized sensor for your specific engine allowing you to install a fully independent wiring kit that has full instructions without the need to purchase anything from a breakers.

if the new wiring kit doesnt fix it then the fan itself could be broken.

 

[Gtedger]

3 hours ago, Lenny said:

I understand that you need to remove the original temperature sensor and tape it up somewhere out of the way in order to keep the ecu happy,

The easiest option for installing the new system would be to purchase this kit from ebay which comes with fitting instructions http://www.ebay.co.uk/itm/292069240854 

if you can measure the thread diameter of the temperature sensor you have; you will then know the size required from the eBay seller I've linked you to there.

The easiest way to find out the size would be to bring the sensor to somewhere like B&Q where they have a range of nuts and bolts in little drawers, 

Search through the nut sizes until you find the size that takes the sensor; you then know the diameter of the sensor and you can contact the eBay seller linked above to purchase the kit containing the correct sized sensor for your specific engine allowing you to install a fully independent wiring kit that has full instructions without the need to purchase anything from a breakers.

if the new wiring kit doesnt fix it then the fan itself could be broken.

 

Hi Lenny, once again many thanks for your help and for coming back to me quick. I will give that a go and keep you posted as to how it goes. Cheers.