My 91 S4 has a big blue electrolytic (Sprague 33000uF, 40V) tie-wrapped to oil cooler. In past I've left it alone or replaced when had to remove.

The capacitor has thick red and black cables going to connections under mass of insulating tape wrapped round capacitor (I removed the tape for the photo). The red wire goes back through hole cut in rear alt cowl. But I'm looking closely at oil pan gasket so noticed that the black cable has been cut just before it enters the alternator cowl! It doesn't look factory...

Given one connection cut I may as well remove the whole thing. But what could it have been used for in first place, and any idea why someone would have cut the ground connection to it? It must have been used to smooth the supply from alternator, but if necessary then why not factory part doing the job? I am baffled.

Anyone want to give it stay of execution before I cut it out entirely?

Thanks

Adrian

 

Hi Adrian,

Absolutely no idea! It's not factory fit, unlikely to be dealer fit and doesn't look like part of the factory alarm, but could be part of a bodged alarm installation/removal?

 

That is massive. Definately not factory. Some large stereo systems use capacitors to help supply current during high cyclic or random demands (think big bass).

 

ya, that is a stereo add on...

 

It was likely used for audio noise supression - though it was unlikely to have been particularly effective - it probably helped a little.

It is not particularly big - say compared to this: (500,000uF)

Alan

 

Thanks gentlemen. The PO did install a separate rear amp so it sounds like it was smoothing for that. I don't turn volume up high enough to shake the car so I'm sure it will be fine without it, and I won't have to pfaff around with it in future.