Aircon Blowing Fuse

kiwi · Post by **kiwi** » Sun Jan 02, 2011 10:35 pm

Not sure how related to the leakage of green blood on the belts and aircon motor. So lets explain.

Couple of days ago the battery warning light came on and with it I lost the fan and indicators! I thought at first that was a sign of the Alternator going! So I did an alernator swap only to find out that it was the FUse in F2 with is the aircon, fan and indicators

Replaced that fuse and today it went again only this time I also had the added green blood in the area probably a result of dislodging a weak pipe when I replaced the alternators.

So not sure if that green blood would couse the belt to slip and result in a coincidental second fuse blow?

Typical hottest time of the year and the flippin aircon goes on the fritz.

Post by **Defender110** » Sun Jan 02, 2011 11:01 pm

Can'y see how a slipping belt would cause a fuse to overload, more likely to be fan siezing causing overload.

johnbird · Post by **johnbird** » Sun Jan 02, 2011 11:28 pm

i agree with the above.a slipping belt would put less load on the system and reduce the chance of blowing a fuse surely?

are bxs prone to blowing fuses? are they prone to leaking lhm under pressure everywhere?

Post by **mat_fenwick** » Mon Jan 03, 2011 12:04 am

At what point did the fuse blow? Straight away or when you operated the fan, A/C (& fan) or indicators? That may give you an idea as to what circuit the fault is in.

kiwi · Post by **kiwi** » Mon Jan 03, 2011 12:31 am

Yes I think I sent you on a bum steer by mentioning the LHM leak.

The First Fuse blew before the Leak!

Mat, First time it went I had no idea it had gone just the sudden tell tale sign of a car interior warming up and the battery light as I cruised along at 100kph with blower going, not touching anything electrical.

Second time it did it was pretty much within a few minutes of turning it on and blower on full! I heard the fuse pop as the tray was still dangling down. Pain in the butt because I then found someone on my tail when I needed to indicate to pull over, of course no indicators once the fuse is gone

oh and kiwi drivers do not understand arm signals

kiwi · Post by **kiwi** » Mon Jan 03, 2011 9:12 am

Sods law carried a spare fuse this time and the fuse did not blow, so no idea what the fault was or is. However a service of the aircon system is probably way overdue.

The thought of more of the 30c temps and humidity we all ready have had here and its only early January without aircon is something I do not realish much! SWMBO is already complaining about the heat in her unairconditioned car

Post by **mat_fenwick** » Mon Jan 03, 2011 9:13 am

If it coincided with blowers on max I wonder if it is a short within the full speed relay (if fitted?) part of the blower circuit.

kiwi · Post by **kiwi** » Mon Jan 03, 2011 9:19 am

mat_fenwick wrote:If it coincided with blowers on max I wonder if it is a short within the full speed relay (if fitted?) part of the blower circuit.

Thanks Mat thats somewhere to look! I rarely put it on full speed and for some reason I did not feel complelled to do that today. My gut feeling was on full speed blow the fuse would go as well.

Next question where(if fitted) would this relay be located?

Post by **mat_fenwick** » Mon Jan 03, 2011 11:31 am

Under the steering column, bolted to the metal pressing that supports the shaft. From memory (5 years ago!) 2 fat blue wires going to it and a couple of yellow smaller ones.

If it only happens with full speed AND A/C on maybe the fuse rating is marginal - is it correct or just the same (possibly incorrect) value as before?

kiwi · Post by **kiwi** » Mon Jan 03, 2011 6:13 pm

mat_fenwick wrote:If it only happens with full speed AND A/C on maybe the fuse rating is marginal - is it correct or just the same (possibly incorrect) value as before?

Book says 25amp the first fuse was 25amp the second 30amp as is the current one. Not to happy with that situation without knowing a cause or where to look but you gave me some good insight where to look.

Vanny · Post by **Vanny** » Mon Jan 10, 2011 10:38 pm

LHM getting into the magnetic clutch on the compressor and shorting it out? A little bit of driving and what LHM isn't thrown out by centrifuge will burn off/evaporate leaving you totally stumped as to what caused the fault. Well it's a possibility.

I'd consider disconnecting the pump and see if the fuse still blows, that would rule it out at least. The blowers are on a seperate circuit so should still run.

kiwi · Post by **kiwi** » Mon Jan 10, 2011 11:13 pm

Up until yesterday with the local mech shop closed I did not risk another fuse blow so kept the fan speeds to the lower settings.

What the heck I ran it on Full speed last night ont he way home and the Fuse did not blow, so vanny it looks like what you said about the LHM getting in was right.

I got a nice damp coating of LHM on the Drivers side wheel arch thanks to the leak and lost about 2 litres so thats a lot LHM dripping on to the Compressor.

Something else learned.

Vanny · Post by **Vanny** » Tue Jan 11, 2011 5:09 pm

You'll probably find a can of electrical cleaner (using the 'hose' attachment) should clean it up without turning a single bolt. Worth a try anyway.

kiwi · Post by **kiwi** » Mon Feb 14, 2011 7:23 pm

Just an update

Since the LHM leak was fixed and the AC compressor has dried out any LHM spilt on it there have been NO further incidents of Fuse Blowing.

Which is great considering how warm its been lately.

Of course once the winter comes can guarentee those few days I want some heat in the car the heater Tap which has been closed for a few months now wont budge. But at least I got Aircon still

electrokid · Post by **electrokid** » Mon Feb 14, 2011 8:11 pm

But at least I got Aircon still

Excellent

Fuses can wear out ! Because the current they normally run at is relatively close to the current at which they will blow, fuses typically run hot. In use, the frangible

element expands and contracts as the load is switched on and off and this causes straightforward metal fatigue. Always best to replace a fuse with a brand new one rather than one from the junk box for that reason.