quest63
Active member
Sinister? like gremlins? green gremlins.....Pac.........
Help Support ProjectPuma:
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Anonymous
Guest
God knows!!quest63 said:
Can someone please look at these two wiring diagrams:
How I understand those diagrams is, the ECU uses the same wires to turn on the fan(s) which tells me that if it can turn on the fans during air con or missing temp sensor, it should be able to turn them on when the coolant gets hot....???
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Anonymous
Guest
This really doesn't make any sense...
I know the ECU sends 5v to the coolant temp sensor.
I know the ECU forces the high speed fan on when I pull the plug off the coolant temp sensor. So, the ECU knows when it doesn't get a return voltage, so therefore the wire between the temp sensor and the ECU is ok.
I know the high speed fan relay works - fan comes on as above.
I know the low speed fan relay works - fan comes on with air con.
I know the ECU sends 5v to the coolant temp sensor.
I know the ECU forces the high speed fan on when I pull the plug off the coolant temp sensor. So, the ECU knows when it doesn't get a return voltage, so therefore the wire between the temp sensor and the ECU is ok.
I know the high speed fan relay works - fan comes on as above.
I know the low speed fan relay works - fan comes on with air con.
Ginger Tom
New member
It could be one of the relays breaking down when they get hot, I cannot remember if you have changed them or not but then again I have had instances of new out the box relays being fubar when they have been tried
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Anonymous
Guest
Yes, I've changed the relay.
Is there a separate temp sender for the dash temp gauge?
My TIS shows the sensor under the coil pack does the gauge, but that does engine coolant..?
Just wondering if there is one, maybe the gauge is reading wrong, and the engine isn't as hot as the gauge indicates. Really not sure if I want to risk a total overheat to prove it.....
Is there a separate temp sender for the dash temp gauge?
My TIS shows the sensor under the coil pack does the gauge, but that does engine coolant..?
Just wondering if there is one, maybe the gauge is reading wrong, and the engine isn't as hot as the gauge indicates. Really not sure if I want to risk a total overheat to prove it.....
YOG
Well-known member
Have you got the Haynes Fiesta manual?
My scanner is not working at the moment, but in section 12-24, Diagram 3, the engine cooling fan (with A/C) diagram shows two relays for cooling and high speed cooling fans, but there is also a third - power hold relay which seems to be linked into the circuits.
My scanner is not working at the moment, but in section 12-24, Diagram 3, the engine cooling fan (with A/C) diagram shows two relays for cooling and high speed cooling fans, but there is also a third - power hold relay which seems to be linked into the circuits.
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Anonymous
Guest
No Manual. I've only got my TIS.... the power hold relay forms part of the electronic engine controls and doesn't look to be connected to the cooling system.
The cooling system wiring diagram I posted further up...
Just found this on the TIS:
Item B6 (C331): Coolant temp sensor - connected to the temp gauge on dash
Item B10 (C113): Coolant temp sensor - connected to the PCM
The cooling system wiring diagram I posted further up...
Just found this on the TIS:
Item B6 (C331): Coolant temp sensor - connected to the temp gauge on dash
Item B10 (C113): Coolant temp sensor - connected to the PCM
YOG
Well-known member
Got the scanner working:
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Anonymous
Guest
Oooh, that looks interesting.... nice one! 
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Anonymous
Guest
I've been doing a bit of fiddling. The power hold relay is the same as the relays for the high and low beam headlights.
With engine off
1. Swapped power hold with high beam - both high beam worked, one low beam worked.... weird
2. Swapped relays back
3. Swapped power hold with low beam - both high beam worked, both low beam worked
4. Swapped relays back
5. Swapped power hold with high beam - both high beam worked, both low beam worked... but didn't before
6. Swapped relays back
Started engine
1. With hand on relays, pulled plug from temp sensor - low speed relay clicks, high speed relay clicks (fan speed accordingly)
2. Replaced temp sensor plug - both fan relays click (fan stops)
3. With hand on relays, pulled plug from temp sensor - low speed relay clicks, high speed relay clicks (fan speed accordingly)
4. Replaced temp sensor plug - both fan relays click (fan stops)
5. With hand on relays, turned on low beam - low beam relay clicks (lights turn on accordingly)
6. With hand on relays, turned on high beam - high beam relay clicks (lights turn on accordingly)
7. Pulled power hold relay - engine dies
With engine off
1. Swapped power hold with high beam - both high beam worked, one low beam worked.... weird
2. Swapped relays back
3. Swapped power hold with low beam - both high beam worked, both low beam worked
4. Swapped relays back
5. Swapped power hold with high beam - both high beam worked, both low beam worked... but didn't before
6. Swapped relays back
Started engine
1. With hand on relays, pulled plug from temp sensor - low speed relay clicks, high speed relay clicks (fan speed accordingly)
2. Replaced temp sensor plug - both fan relays click (fan stops)
3. With hand on relays, pulled plug from temp sensor - low speed relay clicks, high speed relay clicks (fan speed accordingly)
4. Replaced temp sensor plug - both fan relays click (fan stops)
5. With hand on relays, turned on low beam - low beam relay clicks (lights turn on accordingly)
6. With hand on relays, turned on high beam - high beam relay clicks (lights turn on accordingly)
7. Pulled power hold relay - engine dies
A
Anonymous
Guest
I've checked the resistance on the wiring between the coolant temp sensor and the connector to the ECU.
There is also a connector in the circuit behind the drivers side headlight, so I took readings to this first, then from that to the ECU:
Temp sensor +5v to connector = 0.3ohm
Temp sensor ECU return to connector = 0.4ohm
Temp sensor +5v at connector to ECU = 0.7ohm
Temp sensor ECU return at connector to ECU = 0.1ohm
Totals:
Temp sensor +5v = 1ohm
Temp sensor ECU return = 0.5ohm
Making 1.5ohm resistance on whole circuit
The temp sensor has the greater resistance when its cold.
As it heats up, the ECU gets the resistance reading as a voltage drop plus the extra from the resistance in the wiring, so therefore getting a higher volt drop that it should be which in turn tells the ECU the temp sensor is cooler than it is...
Anyone think this is a feasible theory...??
There is also a connector in the circuit behind the drivers side headlight, so I took readings to this first, then from that to the ECU:
Temp sensor +5v to connector = 0.3ohm
Temp sensor ECU return to connector = 0.4ohm
Temp sensor +5v at connector to ECU = 0.7ohm
Temp sensor ECU return at connector to ECU = 0.1ohm
Totals:
Temp sensor +5v = 1ohm
Temp sensor ECU return = 0.5ohm
Making 1.5ohm resistance on whole circuit
The temp sensor has the greater resistance when its cold.
As it heats up, the ECU gets the resistance reading as a voltage drop plus the extra from the resistance in the wiring, so therefore getting a higher volt drop that it should be which in turn tells the ECU the temp sensor is cooler than it is...
Anyone think this is a feasible theory...??
A
Anonymous
Guest
I got a pokey temperature probe thing from Ebay, to test the temperature of the coolant in the expansion bottle.
So, with dash temp gauge straight up in normal = 81.4 degs
Started up again and ran until dash guage reached the 'L' on the word normal = 94.5 degs.
The second time when I opened the expansion tank, water was bubbling from the right side of the engine and flowing up through the small pipe which goes to the top right of the bottle.
It sounded like air, but the coolant level didn't drop.
I started up again and temp gauge dropped to almost the straight up position.
Would the coolant drop almost 15 degs in literally less than a minute?
Thoughts:
Had/got air lock...
Dash gauge not reading correct temperature....
So, with dash temp gauge straight up in normal = 81.4 degs
Started up again and ran until dash guage reached the 'L' on the word normal = 94.5 degs.
The second time when I opened the expansion tank, water was bubbling from the right side of the engine and flowing up through the small pipe which goes to the top right of the bottle.
It sounded like air, but the coolant level didn't drop.
I started up again and temp gauge dropped to almost the straight up position.
Would the coolant drop almost 15 degs in literally less than a minute?
Thoughts:
Had/got air lock...
Dash gauge not reading correct temperature....
quest63
Active member
Random theory time. This assumes that you dont have an ecu problem which is causing the fan not to come on, and that all the wirings ok, and there is no other problem.
Your cars overheating because your water pump isnt working properly, ie poor circulation,another symptom of this is that the water isnt circulating past the temperature sensor properly and therefore the fan isnt coming on simply because that part of the water pathway isnt reaching the temperature to signal the fan to come on.
So my theory says it isnt overheating because the fan isnt coming on but because the pumps not functioning properly.
So maybe try removing the sensor (again) and dipping it in water you know is definately at a temperature that will set the fan off.
I have never had the slightest temp prob, but also I have never been aware of my fan coming on.
Your cars overheating because your water pump isnt working properly, ie poor circulation,another symptom of this is that the water isnt circulating past the temperature sensor properly and therefore the fan isnt coming on simply because that part of the water pathway isnt reaching the temperature to signal the fan to come on.
So my theory says it isnt overheating because the fan isnt coming on but because the pumps not functioning properly.
So maybe try removing the sensor (again) and dipping it in water you know is definately at a temperature that will set the fan off.
I have never had the slightest temp prob, but also I have never been aware of my fan coming on.
charlie0802
New member
- Joined
- Jul 19, 2012
- Messages
- 5
Hey all, first post here, on the above engine diagram what is the y130 c33 sensor? Any help would be much appreciated. Thanks in advance. Am pulling up code p0340 and thinking this may or may not have something to do with it as have replaced my 1.6 puma engine with a 1.7 engine as the 1.6 one blew up and the 1.7 was cheaper to buy as a replacement. May have got some wiring wrong somewhere.
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Anonymous
Guest
I still can't figure this out... fan still not working when it should, so as Quest suggested, I'm going to start looking at getting the ECU swapped over.
So, I'm running a '98 Puma with IR key and a MUFF ECU. As I have the early analogue dash, I'll need an early ECU.
What do I need to get to swap this lot over?
* ECU
* Key (the early keys have a removable blade, so I hope I can just swap this over so I don't have to get another cut)
* The part around the ignition switch..?
So, I'm running a '98 Puma with IR key and a MUFF ECU. As I have the early analogue dash, I'll need an early ECU.
What do I need to get to swap this lot over?
* ECU
* Key (the early keys have a removable blade, so I hope I can just swap this over so I don't have to get another cut)
* The part around the ignition switch..?
