Voltage spikes and relays

[Scott Elliot Gilman]

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.

Scott
1-owner '91 200TQ with 107K
NYC