Mgzt fan issues

[mgzrjake]

Ok but why do I have no cold air when it’s stood still only slight colder on the move all the above had not been answered

[slovcan]

Originally Posted by mgzrjake

Ok but why do I have no cold air when it’s stood still only slight colder on the move all the above had not been answered

An A/C guy can explain exactly how the system works. The fan or forward motion must create airflow through the condensor in order for the refrigerant to do its thing. If that doesn't happen the system pressure will rise to a level that causes the compressor to stop working in order to save the system from damage.

Once your fan is working as it is supposed to, your A/C should also work. Just focus on the fan for now.

Cheers,
Glenn

[mgzrjake]

Originally Posted by slovcan

An A/C guy can explain exactly how the system works. The fan or forward motion must create airflow through the condensor in order for the refrigerant to do its thing. If that doesn't happen the system pressure will rise to a level that causes the compressor to stop working in order to save the system from damage.

Once your fan is working as it is supposed to, your A/C should also work. Just focus on the fan for now.

Cheers,
Glenn

Thank you.

So because my fan isn’t kicking in the a/c is not working correctly so could this be the fact the fan isn’t working so garage saying the air dryer is broken could also be wrong.

Could the fact also be it was left front end open for over a week with no bugs in a/c pipes as was also suggested by the garage man he said moisture has entered the system.

Is there anyway to test and make the fan spin ?

JT

[Arctic]

HI Jake.
I am myself checking a fan off the car today for someone, but I can do that on the T4, being as you do not have one, the best way for you to check the low speed of the fan which works in conjunction with the A/C is follow this below.

A/C all off turn ignition to II then press the demist button on the A/C control panel, once this is pressed look through the front grill of the car is the fan running continually.

If yes then set the internal fan temp to 16degrees or to LOW then see if any cold air is coming out of the vents>

Also in the engine bay feel the A/C pipes one is thin & the large, the latter should feel cool or even cold, the thin one warm.

[SD1too]

Jake; my earlier unanswered question is crucial to diagnosing why your fan isn’t running with a gold resistor fitted:

Originally Posted by SD1too

... is the control box lid on the replacement fan system labelled 'M47' or 'PWM2'?

In other words, did the fan motor, wiring loom and control box assembly you bought definitely come from a diesel 75/ZT? If you don’t know I’m afraid you’ll need to take the bumper off again to find out.

Originally Posted by mgzrjake

So because my fan isn’t kicking in the a/c is not working correctly ..

Correct.

... so garage saying the air dryer is broken could also be wrong.

They’re referring to the dryer or desiccant pack. It’s not an air dryer. It’s sealed and absorbs any moisture from the refrigerant gas and won’t be the cause of your problem.

Could the fact also be it was left front end open for over a week with no bungs in a/c pipes as was also suggested by the garage man he said moisture has entered the system.

Air con. pipes should always be capped to prevent ingress of dust and moisture. However, practically speaking and in our current low humidity weather conditions, you need not worry about a week. A professional mobile air con. specialist would have allowed enough time for stored moisture to be extracted before recharging with refrigerant gas. The fast-fit outfits would not.

Is there anyway to test and make the fan spin ?

The ‘demist’ test checks the slow speed which you say isn’t working. The fast speed can be checked with the ignition on and with a linking wire across pin 2 (black wire) and pin 3 (yellow/grey wire) of the trinary switch 4 pin connector. If the fast speed doesn’t operate then, it suggests that you may have been sold a control box for a petrol engine which won’t work on your diesel.

Let us know how you get on.

Simon

[mgzrjake]

Originally Posted by SD1too

Jake; my earlier unanswered question is crucial to diagnosing why your fan isn’t running with a gold resistor fitted:

In other words, did the fan motor, wiring loom and control box assembly you bought definitely come from a diesel 75/ZT? If you don’t know I’m afraid you’ll need to take the bumper off again to find out.


Correct.

They’re referring to the dryer or desiccant pack. It’s not an air dryer. It’s sealed and absorbs any moisture from the refrigerant gas and won’t be the cause of your problem.

Air con. pipes should always be capped to prevent ingress of dust and moisture. However, practically speaking and in our current low humidity weather conditions, you need not worry about a week. A professional mobile air con. specialist would have allowed enough time for stored moisture to be extracted before recharging with refrigerant gas. The fast-fit outfits would not.

The ‘demist’ test checks the slow speed which you say isn’t working. The fast speed can be checked with the ignition on and with a linking wire across pin 2 (black wire) and pin 3 (yellow/grey wire) of the trinary switch 4 pin connector. If the fast speed doesn’t operate then, it suggests that you may have been sold a control box for a petrol engine which won’t work on your diesel.

Let us know how you get on.

Simon

Will do this is what need to do and follow thank you

[mgzrjake]

[QUOTE=SD1too;2644806]Jake; my earlier unanswered question is crucial to diagnosing why your fan isn’t running with a gold resistor fitted:

In other words, did the fan motor, wiring loom and control box assembly you bought definitely come from a diesel 75/ZT? If you don’t know I’m afraid you’ll need to take the bumper off again to find out.


Correct.

They’re referring to the dryer or desiccant pack. It’s not an air dryer. It’s sealed and absorbs any moisture from the refrigerant gas and won’t be the cause of your problem.

Air con. pipes should always be capped to prevent ingress of dust and moisture. However, practically speaking and in our current low humidity weather conditions, you need not worry about a week. A professional mobile air con. specialist would have allowed enough time for stored moisture to be extracted before recharging with refrigerant gas. The fast-fit outfits would not.

The ‘demist’ test checks the slow speed which you say isn’t working. The fast speed can be checked with the ignition on and with a linking wire across pin 2 (black wire) and pin 3 (yellow/grey wire) of the trinary switch 4 pin connector. If the fast speed doesn’t operate then, it suggests that you may have been sold a control box for a petrol engine which won’t work on your diesel.

Let us know how you get on.

Simon[/QUOTE

Simon most helpful, both you and arctic.
will do both options you suggest, gutted I need to remove the bumper again

[mgzrjake]

Originally Posted by Arctic

HI Jake.
I am myself checking a fan off the car today for someone, but I can do that on the T4, being as you do not have one, the best way for you to check the low speed of the fan which works in conjunction with the A/C is follow this below.

A/C all off turn ignition to II then press the demist button on the A/C control panel, once this is pressed look through the front grill of the car is the fan running continually.

If yes then set the internal fan temp to 16degrees or to LOW then see if any cold air is coming out of the vents>

Also in the engine bay feel the A/C pipes one is thin & the large, the latter should feel cool or even cold, the thin one warm.

Artic I have turned key to pos 2 Econ lit up hit demised button which I take it looks like a fan with lines in it, temp low gave it 2 mins no fan spinning so where does that leave me ?
JT

[SD1too]

Originally Posted by mgzrjake

... Econ lit up hit demist button which I take it looks like a fan with lines in it, temp low gave it 2 mins no fan spinning so where does that leave me ?

It just confirms that your replacement 2 wire, 2 speed fan with gold resistor isn’t working on the slow speed. This could be for many reasons:

• Defective connections to gold resistor.
• Worn out motor brushes (unlikely).
• Petrol control box fitted.
• Defective PCB in diesel control box.
• Wiring fault on loom or feed to it.

As said, the only way to make progress is to whip off the bumper (it will be quicker this time) and start by finding out which control box you have.

Simon

Edit: Jake, you are asking about a ZT aren’t you? It’s just that your profile says ZR.

[mgzrjake]

Originally Posted by SD1too

It just confirms that your replacement 2 wire, 2 speed fan with gold resistor isn’t working on the slow speed. This could be for many reasons:

• Defective connections to gold resistor.
• Worn out motor brushes (unlikely).
• Petrol control box fitted.
• Defective PCB in diesel control box.
• Wiring fault on loom or feed to it.

As said, the only way to make progress is to whip off the bumper (it will be quicker this time) and start by finding out which control box you have.

Simon

Simon yet again thank you.

Yes bumper will be removed and box looked at along with connections on gold risister not sure it will be that as it was jointed correctly and you will tell me it doesn’t matter which way but I did do it forward facing. I still have the old fan so I might just re plug that in and try the fan test with what arctic has said above will keep you up dated if that’s ok.

JT