Blower Fan Not Working - Air Con Light Not coming On

[je72]

Hello folks! Long time since I've posted, I'm still around and still got the MR2, however I've hardly driven her for the last 18 months because of the you know what! However, I've been using her again for the last week or so, did a couple of long runs and she's been perfect and lovely to drive.

Until today, after I'd popped into a garage to get a Costa from the vending machine I got back into the car and noticed that the air con light wasn't on (it had been working fine for the previous 60 odd miles) then I noticed that the blower wasn't coming on, then I noticed that the led on the air con wasn't coming on. When I press the air con switch the revs go up and I can hear what I assume is the condenser kicking in (led still not coming on though) but of course there's no cool air because the blower isn't blowing. I was aware of a very feint kind of scraping noise from the blower the last couple of times I drove it, which I had assumes was a leaf in the pipe somewhere (I've had something similar on previous cars) It may just be a coincidence, but maybe it was the death throws of the blower unit? Obviously I'm hoping that it'll just be a fuse, it's been excessively hot here in the midlands the last few days, I would guess that it was circa 30°c when it stopped working, which made for a sticky ride home, not sure if that could've been a contributing factor to it's giving up.

What are peoples suggestions to try please?

Thanks in advance of any assistance
Jade

[Frank Rabbets]

I would check that the compressor is actually turning intermittently. Best viewed with a torch. ( The compressor pulley always turns but the end plate should click in and start turning the compressor internals).If the compressor is not turning then it sounds like the auto switch which senses the gas pressure has shut the system down due to low gas. If the compressor is not turning then I would search round for a leak with a UV torch. (cheap off ebay). The system may not have dye in though if it is the original oil/gas. In that case recharge with gas and dye. Running after a recharge is a bit risky though as if there is a leak some oil will have been lost and there is no way to check the oil "level". The reason for the safety pressure switch is that if gas pressure is low there may be a leak which could have caused lost oil. Running with low oil seizes the compressor. If it were mine I would guess at adding 4 ounces of oil and hoping for the best. The alternative is to strip down and drain all components. Dry all out and add the whole recommended oil amount on regas.

[je72]

Hi Frank, thanks very much for that detailed reply  Would the condenser not working, in turn stop the fan blower though? I'd have thought the blower would work independent of the A/C because you can normally run the fan without the A/C if the temp doesn't require actual cooling. If you can't tell, I'm pretty inexperienced when it comes to troubleshooting car problems (hence the post) I'm currently trying to work out which is the blower fuse just to try that 1st, I think it's number 13 (7.5a) in the passenger side, dash fuse panel. I'll try that 1st and see how I go, unless you or anyone thinks I'm wasting my time with fuses

[je72]

So I checked the fuse box and number 13 (FAN-IG) 7.5amp was intact, so I checked number 10 (HTR) 10amp which I had thought meant heater and in fact means "Air conditioning system"! And guess what, it was popped. I'm going to try a new fuse, unless anyone thinks that the fuse going could be an indicator of something more serious? (I know you'd probably need a crystal ball for that though)

Just in case I'm doing the right thing and this helps anyone in the future, I've ordered a set of "mini" car fuses from amazon for £3.99 on prime: https://www.amazon.co.uk/dp/B0967SZDWW

[Bossworld]

So I checked the fuse box and number 13 (FAN-IG) 7.5amp was intact, so I checked number 10 (HTR) 10amp which I had thought meant heater and in fact means "Air conditioning system"! And guess what, it was popped. I'm going to try a new fuse, unless anyone thinks that the fuse going could be an indicator of something more serious? (I know you'd probably need a crystal ball for that though)

Just in case I'm doing the right thing and this helps anyone in the future, I've ordered a set of "mini" car fuses from amazon for £3.99 on prime: https://www.amazon.co.uk/dp/B0967SZDWW

It's unlikely (though not improbable) a fuse would blow of its own accord.

Perhaps something has jammed the blower motor? You'll sharp find out anyway once you swap the fuse

[virginpaul]

A fuses purpose is not to protect the component at the end of the wire, but to protect the wire and so the vehicle.  If a component such as a motor is seized or jammed by something it allows a high current to pass.  The fuse protects the wiring from becoming a heater and melting and causing fires.

Always worth trying a replacement correct rating fuse once, the seize may have been a one off due to the high heat expanding/mis shaping ducts or cowls and jamming the fan, but from my line of business - one reset is enough. 
I've known of aircraft circuit breaker's being reset by crew trying to recover a system so many times they weld closed and then the wiring's melted and caused localised structural heat damage - way harder to fix.

Given the squealing before your pit stop, I'd be looking at a blower motor before delving too deep into the aircon.  The click, revs increase and cooling fans kicking in are all signs of a healthy aircon system, but with no actual blower operating to pass air over the evaporator, there may be a build up of refrigerant pressure causing the compressor to cut out.

Let us know what you find please

[Frank Rabbets]

There are 2 "blower" motors. 1. The one cooling the condenser/radiator at the front of the car just behind the bumper. 2. The one in the car blowing air through the A/C evaporator/radiator.
Sounds like you have an electrical problem on the circuit of the blown fuse. Most likely a component on that circuit rather than the wiring itself.
Very unlikely that a new fuse will pop straight away unless there is a fault elsewhere.
You need a wiring diagram to see what components are served by that fuse and check those one by one.

[je72]

Hi folks, thanks for all the advice, I've gained some useful insight there. The new fuse resolved the problem and it hasn't recurred (yet) however I can definitely hear a kind of scraping noise when the heater blower fan is switched on. So I'm going to pop it open and see if it's just a leaf, failing that it'll be a new blower motor. Hopefully that's the cause of the issue.

[virginpaul]

Good troubleshooting.  Worth 1 try replacement of a blown fuse before you start dismantling complex system components.

Knew exactly which fan you were referring to when you said "blower motor" too.  Can't say I've ever referred to a rad or aircon condenser cooling fan as a blower motor before.  But everyone has their own terminology.

Let us know if you find anything in the motor casing/ducting.  My moneys on a sorry bearing or deformed housing.

[je72]

Another update, the fuse blew again the day after I changed it so obviously there was a fault somewhere. Because of the noisy fan that seemed like the most obvious 1st thing to look at, Dick Sloan supplied a used one, I spent 3 days psyching myself up to the job as it seemed to involve partially moving the dashboard. I shouldn't have worried though as it was simply a case of unclipping the glovebox, then unclipping passenger side kick panel (which involved unclipping the door scuff strip first) that gave plenty of access. Unclipped the power cable (simple pinch and pull) then 3x8mm bolts (had to support it as it heavy and wants to fall down) popped the replacement in and reversed the removal, replaced the blown fuse and hey presto, a working fan and air con which has now been working for over 100 miles. Happy days.

As a little side issue, Dick recons it's the only fan he's sold from one of these in 12 years of breaking mk3's! As I only do a bout 2k per year, maybe a previous owner loved having the fan on!

[virginpaul]

Good fix and thanks for the update.
Cheaper than dismantling the system....