Technical Heater blower challenge

[Italian Job]

Bloody hell where is that coming from
Do the same leave the relay out and the reversing light switch disconnected

 

[Arabyc1]

Relay out reverse switch off redistance 2 ohms on negative side of fuse

 

[Italian Job]

Ok sorry about this but now disconnect the rear light cluster the relay out and the reversing light switch disconnected

this 2 ohms is the problem i think

 

[Arabyc1]

relay out 2 ohms

switch out as well 2 ohms

passenger side rear cluster out as well 60 ohms

reconnect cluster test again still 60 ohms

unfortunately pouring with rain and nowhere to check without getting soaked so sorry was just getting going

 

[Italian Job]

its a lot better will study the diagrams
when ever you can leave the cluster out and reconnect the reversing light switch and re measure then connect the relay and measure again.

RAINING just to let you know its bloody hot here. I would love some rain

 

[Italian Job]

Got to go and eat now will check after but no probs if you cant do anymore today

 

[Arabyc1]

I will double check all this again when I get a chance and also leave cluster out and switch in . A Scottish summer can last days or hours.

 

[Arabyc1]

Ignition on ALL CONNECTED = 12volts 90ohms

Relay removed/ Reverse switch removed = 12volts 6ohms

Relay removed/reverse switch removed/back cluster removed =12volts 6ohms

Relay removed/back cluster removed /CONNECTED REVERSE SWITCH = 12 volts 6ohms

Back cluster removed/CONNECTED RELAY/CONNECTED REVERSE SWITCH=12 volts 77ohms.

These are all double checked taking readings as i disconnected then taking readings as I reconnected again I hope this is enough information.

 

[Arabyc1]

An opinion from the maintenance lad at work.

All disconnected, fuse in, ignition lights turned on, all okay, turn key on ignition for engine on fuse blows.

Tested resistance when engine on wobbles between 0.7 and 0.8 ohms.

Calculation 12volts divided by 0.7 ohms is around 17 amps.

Hence will always blow 7.5 amp fuse.

He said he felt we had proved all relay, clusters ,switch are okay. He feels we have a short at the back of the fuse box?

Hope this helps and moves us a step closer

 

[Italian Job]

Cant help tonight as travelling home for the weekend but can tomorrow. It could well be the fuse box inside the car or the one where the relay is. Tomorrow we can prove which one

 

[Italian Job]

Just a thought all OK until you turn the engine on. What happens if you remove the fuse start the engine then with it running replace the fuse ????????'

 

[drjod]

fixed my mates blower last week, his blower was arcing at the connector under the glove box, does yours have a pollen filter, and is it blocked, this was the cause of my mates punto mk2's blower over heating and melting the connector, causing the short, sorry if this has been covered, but his is fine now...

 

[Arabyc1]

Just a thought all OK until you turn the engine on. What happens if you remove the fuse start the engine then with it running replace the fuse ????????'

This appears to be the case not definate but appears to be. I think when the engine is running the resistance is 0.7 and wobbling this would blow the fuse. You guessed it raining here just now forecast is better later.

 

[Arabyc1]

fixed my mates blower last week, his blower was arcing at the connector under the glove box, does yours have a pollen filter, and is it blocked, this was the cause of my mates punto mk2's blower over heating and melting the connector, causing the short, sorry if this has been covered, but his is fine now...

Thanks for the input have taken resistor ,blower and connectors apart under glove box all appear sound

 

[Italian Job]

You dont have Air Con but the wiring maybe there ( I think Ziggy has the wiring but no Air Con) that also could e causing the problem.

We need to narrow it down even further

 

[Arabyc1]

I will give this a check later today any idea where air con wiring is located.

Also when checking negative fuse terminal in interior fuse box I did this with heater blower switch turned off at zero if I turn this to 1 2 3 0r 4 option would this make any difference ? Think progress has been made hope I'm making sense.

 

[Italian Job]

Heater blower switch to 0 is good

Just checking now to see where you can look to see if air con wiring is in place

 

[Italian Job]

The only way ahead i can see at the moment is to disconnect the cable from behind the blower sppeed switch and then re measure the risitance and see if the 0.7 ohms is still there

 

[Arabyc1]

Any idea how to get at the blower switch cable?

 

[Italian Job]

never taken one apart so sorry dont know. I think you have to undo the screws holding the centre console so when its loose you can get your hand behind it and disconnect the connector