07 impala AC blowing fuses

[muddpuppy]

OK So I drove through a couple really big semi deep 2' or so flooded out roads. More or less forced through them. This was on Friday I had no issues Friday, Saturday, and most of Sunday. Sunday afternoon I ran to the store and no air. This morning no air so I dropped it off at a local shop this morning paid my $39+tax for the diagnostics.

Blowing fuses could be the relay, swapped the relay with the fule pump car drives fine AC still blows fuses. I aksed what the issue was he says electrical. $100 per hour + parts to track it down. (Fair Price) I asked what was tested to confirm a electrical problem. He said nothing it's blowing fuses.

1. the diagram for this ciruit looks pretty simple (not to may wires)

2. Could a bad compressor cuase irregular voltage and pop a fuse?

3. Shouldn't the $40 diagnostics cover this testing to tell me what needs to be fixed?

Any thoughts?

[muddpuppy]

I would also like to add that I can replace the 10amp fuse start the car and cold air flows until I put the car in drive and start down the raod. Fuse then pops and the warm air flows.

[mnviking28]

Typically the issue on this is the compressor kicking on causing the fuse to blow. I think that the combination of the extra load of the engine and the start up of the a/c clutch kicking in is causing the fuse to blow. Unfortunately, this is usually only cured by replacing the clutch/and or a/c compressor and clutch combination. Not knowing the ability of the tech you talked to, I am kind of surprised that he never suggested this as a possible cause.

[Macgyver55]

I would also like to add that I can replace the 10amp fuse start the car and cold air flows until I put the car in drive and start down the raod. Fuse then pops and the warm air flows.

Try putting in another fuse and instead of driving, rev the motor in neutral up to 2500 or so to see if it blows, then reply back... I'd be interested to find if is an RPM initiated problem or a torque caused problem. Possibly the torque of the motor is causing a harness to rub on something and short out.

[delcecchi]

Just out of curiosity, since it started not too long after immersion, would the water have gotten high enough to get the compressor clutch or wiring wet? I would think getting dunked could have done a number on something.

Why would RPM or load affect the current drawn by the AC clutch?

[muddpuppy]

well I can let it idle and I can rev the motor but the second I start down the road it blows the fuse. Looks like I will be without aircondition for some time..... quotes from 1000-1500

[Macgyver55]

I'd personally be checking the harness real close to see if it is rubbing or pinched somewhere when the motor torques. If it works ok at idle and revving up, but blows a fuse with a load on the motor it makes more sense that it would be a harness or wiring problem rather than a compressor problem. The compressor has the same load on it whether you are driving or sitting still. I'm still guessing its a harness issue.

Try holding the brake, putting it in gear and load the motor to see if it blows then.

[Jeremy airjer W]

3. Shouldn't the $40 diagnostics cover this testing to tell me what needs to be fixed?

The a/c performance test typically consists of a visual check of the belts and hoses and other components. A set of a/c gauges will then be hooked up to see how the a/c is performing. If pressures are low a die will be added to the system and it will be checked for leaks. if no leaks are found the system will be topped off.

You can think of the A/c performance check as a mechanical and integrity check of the a/c system.

If the gauges are hooked up and the static pressure is enough to turn everything on but nothing is turning on than its not an "a/c performance issue" its either an electrical or computer related issue which are "diagnostic" issues. Many times a scan tool is required to confirm a/c data and a wiring diagram will be printed off. As soon as I plug in my scan tool its $99.95!

If labor rates are around $100 dollars than $40 covers less than a half hour of time. The performance check itself will easily take that amount of time.

[delcecchi]

I always figured the "performance check" was sort of a loss leader to get folks in the shop. If the AC was working well they wouldn't need a performance check.

[Jeremy airjer W]

90 percent of a/c problems are mechanical in nature. Whether it be leaks, bad compressors, etc. So the performance test does cover and find a majority of the a/c problems.

[muddpuppy]

Makes sence, I guess my expectations were that they would find the cause of the problem. Then let me know the corse to fix, not quote me $100 at unlimited hours + parts to find and fix the issue. I think the least they should have offered waS to waive the $39 seeing all the guy did was check the fuse whatch it pop a couple times and call it an eletrical problem, and I am sure if I pushed for the fix they would accomodate but the car is not worth the cost of the fix to me.

Thanks for the time

PS I checked over all the wires and they look good no freys nics cuts that I can tell. I can not seem to find my MULTI meter so I did not test voltage yet.

[Jeremy airjer W]

Voltage is not the issue!

You would probably want to check the compressor clutch for resistance and short to ground. With the compressor unplugged you can install a fuse, turn the a/c on, and see if the fuse blows. If it doesn't until you plug the connector back in than it's the compressor. If it does with it unplugged than there is another issue.

So the shop shouldn't get paid for the service you requested? They did determine that the mechanical side of the a/c system was fine and that it was the control side of the system that was at fault. Something you didn't know or didn't think to check before you brought it in.

I'm not arguing with you, i'm just tired of people thinking everything is free. It's not there fault that the service you requested was not the correct service needed. Regardless if it took 5 minutes or an hour the fee stays the same. The shop did what you asked and they should be compensated.