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electrical 'arc' sound coming from behind central dash area - 944S2
Just drove the S2 for a few minutes... at the job now so I won't be able to look at it till later. A few minutes into the drive a sound began behind the dash that sounded like electrical arcing. I pulled over to listen and confirmed it was not coming from the speakers/stereo, but appears to be coming from behind the central dash.
When I depressed the AC button (AC was off because its currently not functioning due to a leak) the arcing sound stopped. Disengaged the AC and the arc sound began again. I was able to replicate several times.
Anyone know what the issue is? Of course, I plan to address it as soon as possible. Am I risking an electrical fire if I drive it more?
No direct experience to relay. Hopefully you can reproduce it with the car idling in the driveway. If that is the case, start pulling fuses one at a time and see which one makes it stop. Start with the fuse(s) for the AC.
Alternatively, wait till it is good and dark and do a close inspection.
The AC is s strong clue and I would guess it is going to turn out to be a relay.
First place I’d look is at the two large puck resistors behind the dash on the firewall which control the cooling fans. The wiring insulation going to those resistors has been known to break down and cause bare wires that could short (or “arc”). I believe the cooling fans are tied to the ac circuit in that, when you turn the ac on, the fan relay turns one of the fans on high speed for condenser cooling.
Edit: just saw this is for an S2, the early cars had those resistors behind the dash but later are on the other side of the firewall, so unlikely that’s your issue. Btw this is what they look like when the insulation breaks down.
Just noticed this in my S2 cabriolet. The sound comes from the right side of the dash, near the airbag. Goes away when the AC is on, returns when it is off.
07-06-2018, 02:53 PM
electrical 'arc' sound coming from behind central dash area - 944S2
