Air Con Fuse Keeps Blowing - Help Please!

[Easy Rhino]

The V90 (98) does not get driven much since #2 son moved to the mainland, but it's the beach beater, home store hauler, and guest transportation (we get a lot of company).

Anyway, the AC quit blowing cold, and tonight I got around to checking it. Seems that the AC fuse was toast.

Replaced the fuse (it is 15A) with a new fuse that lasted about 5 minutes, during which time the AC worked as new, then the fuse blew.

Replaced it one more time - same result - the AC works great (compressor spins, cold air issues, life is good), then after about 5 minutes the fuse blew again, stopping the compressor.

Guests arriving next Saturday, I need to have this thing working.

Any assistance would be greatly appreciated.

What would you check next?

[Easy Rhino]

Update:

Since the Compressor spins and the AC blows cold when the fuse is not blown, I'm thinking that the compressor is okay (I'm thinking that a high friction compressor would cause an immeidate blown fuse)..

And,

Since the fuse blows after several minutes of running the AC system, I thinking that a short to ground is not that likely (I'm thinking that a direct short would cause an immediate blown fuse).

Therefore;

I'm concluding that the culprit is most likely the AC compressor electromagnetic clutch.

Thoughts?

Has anyone replaced one of these buggers, preferably without pulling the compressor out (save the AC freon charge, just replace the clutch coil)?

[david philips]

check all the wireing first allways start with the cheap and easy things first,i know a direct short would cause a fuse to go straight away but with wireing sometimes theres something rubing ,and can cause an intermitant fault like this one ,then it gets worse,good luck.

[Easy Rhino]

Originally Posted by david philips

check all the wireing first allways start with the cheap and easy things first,i know a direct short would cause a fuse to go straight away but with wireing sometimes theres something rubing ,and can cause an intermitant fault like this one ,then it gets worse,good luck.

Thanks,

Tomorrow (It's late here now) I'll take voltage, resistance, and ground readings to try to find any 'leaks', shorts, or high resistance connections.

[Easy Rhino]

After additional research, I think it boils down to one of the following causes:

1 - Dodgy wiring from the power supply, downstream (load side) of the fuse, including high resistance connections or shorts to ground intermittent or just low resistance to ground.

2 - Clutch coil is toast.

3 - Clutch plate worn down so far as to cause the clutch gap to be too wide, resutling in too high current to engage the clutch fully (I don't think that this is a more likely cause).

After checking for indications of #1 andd #2, if I come up empty handed, I might try the clutch gap adjustment.

[WirralNick]

Hi, did you find the culprit, I have similar in 2012 d5. With Aircon off, engine runs fine, with Aircon air, air is ice cold for 5mins or so then the fuse blows which also affects engine idle.

Easy to replace the fuse. But it would be great to get that cold air blowing.

Any pointers please?

[Forrest]

Neither of the people who contributed to this thread have been on the forum for at least five years and this is the wrong section for your car.

If you’ve got a Zexel compressor with a magnetic clutch then I’d feel inclined to check/test that first. It could be shorting internally or leaking a spike when it cuts out.

Good luck tracing the fault.

[Laird Scooby]

A 1998 V90 is basically the same as a 1997 960 so he is in the right place.

If memory serves, the compressor clutch fuse should be 30A but please check your handbook/workshop manual to confirm this. Certainly in my 760 the heater fan/AC fuse is 30A and the 760 is just an older version of a 960. It would certainly explain why a 15A fuse blows so easily!

I'd say check what the fuse should be (fairly sure it will be 30A) and replace with the correct value and don't allow people to meddle with the fusebox in future!

[Forrest]

Originally Posted by Laird Scooby

A 1998 V90 is basically the same as a 1997 960 so he is in the right place.

Agreed, but that’s the original 2011 thread. The revival is about a 2012 D5. Not sure whether that uses the same compressor.

[Laird Scooby]

Originally Posted by Forrest

Agreed, but that’s the original 2011 thread. The revival is about a 2012 D5. Not sure whether that uses the same compressor.

Very good point! I missed that, sorry! Only saw the bits about the 1998 V90 and somehow didn't see the 2012 XC90 D5

If memory serves, the later car uses a Variable Displacement compressor so the compressor runs all the time the AC is on, internal valves vary the load (and hence displacement) of the compressor to vary the amount of cooling it actually gives.
Generally because they are configured to a "soft-start" by the valves reducing the load on the compressor until the clutch is fully engaged, a smaller coil is used for the clutch so a smaller fuse would likely be needed.Reading the post i missed, i'd guess (without knowing any more clues) it's either low on gas so is trying to load up the compressor for more cooling or there is another problem somewhere with the system.