2001 XC70 Blowing Fuse#8 and Accelerator Cut Off with Brake

aronthemechanic2016 · Post by **aronthemechanic2016** » 12 Feb 2016, 14:06

Thank you again for the response. Yes, the TPS will probably needs replacing as soon as I feel symptoms arising. Since buying the XC, I've learned so much about the infamous ETM issues. We've already fixed the cut wires through the tailgate hinge (only 2 were in tact) and that seems to have fixed the stuck key in ignition and stuck shifter. Will there be any disadvantage replacing the TPS blindly with contactless ones on ebay? It probably doesn't need one now, but if I have to do it down the road, might as well do it now.
I'll get the meter out and measure the resistance of the coil after I get out of work. The 14-pin connect coming out of the fusebox, pin 6 is the grey wire I cut, and is supplying 13 volts. Does this wire go straight to the compress coil connector, or does it pass any sensor, relay or switches. I don't want to bypass anything that will cause damage to the coil.

Post by **abscate** » 12 Feb 2016, 17:05

On ME7 the compressor is switched on by the ECU - the grey wire does not go to the compressor, IIRC.

goldsoundz · Post by **goldsoundz** » 14 Feb 2016, 13:53

This is so weird but I am experiencing the same exact problem right now. My serpentine belt snapped yesterday- luckily I had a replacement on me and was able to replace. When I started the car back up I was getting REDUCED ENGINE PERFORMANCE message with codes 9530 and 9540 the accelerator pedal. Now I keep blowing fuse #8 just like you are. Is it possible that the AC compressor seized... leading to the belts snapping... and thats what is making fuse #8 blow? At the moment I don't care about the lack of AC since it is freezing here but the acceleration issues are a problem. Have you gotten any further in your investigation?

goldsoundz · Post by **goldsoundz** » 14 Feb 2016, 14:28

I went ahead and did what you did and clipped the #6 pin gray wire. I was able to reset the REDUCED ENGINE message and the acceleration issues are gone for now. Obviously the real issue remains- what is causing the fuse to blow? Seized AC compressor? Wire shorting out somewhere?

aronthemechanic2016 · Post by **aronthemechanic2016** » 15 Feb 2016, 17:16

I'm glad this forum has helped another member. I still have not figured out how the wire from pin#6 and the compressor coil connector is grounding. In your case, can you turn the compressor by hand to see if it had seized? A seized compressor pulley may have caused your belt to break.
In my case, the compressor pulley tuns easily, and the coil resistance is 4.7 ohms. I've googled all weekend to find an electrical diagram of this cable, but could not. I was hoping it would be as easy as running a new wire, but as mentioned by abscat, there is the ECU that goes between the two points. Can anyone help with a wiring diagram of the main fusebox and the AC compressor coil? Thanks.

goldsoundz · Post by **goldsoundz** » 16 Feb 2016, 16:55

Update: Four days after the first belt snapped- the replacement belt snapped. Granted the replacement belt was used but in reasonably good condition that I kept around in case of an emergency. Surely this points to a bigger issue. I turned the AC compressor pulley wheel and while it does turn... it does not turn as smoothly as I would have anticipated and seems to have some resistance there. I must mention that it is cold here in the midatlantic and the AC was not turned on either time the belt snapped. Does this make sense to anybody? Should the AC compressor wheel turn freely so long as the AC is off? My next step is to put a brand new belt on and get the car home but I am at my wits end with this car.

JudgeRat · Post by **JudgeRat** » 16 Feb 2016, 17:43

goldsoundz wrote:I turned the AC compressor pulley wheel and while it does turn... it does not turn as smoothly as I would have anticipated and seems to have some resistance there. I must mention that it is cold here in the midatlantic and the AC was not turned on either time the belt snapped. Does this make sense to anybody? Should the AC compressor wheel turn freely so long as the AC is off? My next step is to put a brand new belt on and get the car home but I am at my wits end with this car.

If it is like my s60, the A/C will operate year round if you keep the climate control in the "Auto" setting. This is to help keep your windows from fogging up so easily from the moisture you expire in the winter months and in transitional weather. Also, if the A/C clutch is seizing, that could account for the pulley not turning completely freely even when the A/C is completely off.

goldsoundz · Post by **goldsoundz** » 16 Feb 2016, 20:25

Thanks for your response. I do not use my climate control in the AUTO setting- although I wouldn't doubt if it may accidentally be put in that position from time to time. At the moment all signs are pointing to the AC clutch seizing. I'm guessing there is nothing I can do here besides a total replacement? Nothing to lubricate or anything? While I consider myself a fairly knowledgeable mechanic- I admittedly have shied away from doing any service to the AC systems up until this point.

2001 XC70 Blowing Fuse#8 and Accelerator Cut Off with Brake

Re: 2001 XC70 Blowing Fuse#8 and Accelerator Cut Off with Brake