Voltage spikes and relays

Kent McLean kentmclean at comcast.net
Wed Feb 27 17:00:44 PST 2008

Scott Elliot Gilman wrote:
> My '91 200 TQ has developed intermittent electrical spikes, which  
> causes problems with the audio system.  The radio and speakers were  
> checked out, and they are not causing the problem.  The audio tech  
> believes the problem may be a result of a faulty relay.  Where can I  
> find a schematic diagram showing the relays?  How many relays are  
> there on this model?  Also, what do the relays cost?  I've heard that  
> they may be about $60 each.  I suspect they're more.  I don't know  
> much about the car's electrical system; fortunately I've got Becker  
> Audio in Hatboro, (north of Philadelphia) doing the work.  Becker's  
> rates are fair and the shop has an excellent reputation.     Thanks  
> for the help.

Define the problems.  If the audio system hums and pops, it may not be 
electrical spikes. The old Bose system is infamous for its capacitors dying, 
causing the audio problems. You can pull the speakers, take out the amps, and 
replace the capacitors (Brett had a write-up), or ship it somewhere to have it done.

Kent McLean
'99 A4 Avant, w/ quattro, V6, Tiptronic. "Yeah, Baby!"
'94 100 S Avant, "Moody"
'91 200 TQA #1, undecided
'91 200 TQA #2, up in smoke 2
'89 200 TQ, "Bad Puppy", up in smoke

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