Contact Brookhouse Parts LTD at ipswich on telephone no 1473 218806 ask for Simon he carries all sorts of spares for the older volvo i will also give you his e-mail address
brookvolvo@btconnect.com..you could also look at Website..
www.classicvolvoparts.co.uk dont expect a quick answer but befor he went on his own many years ago he worked for Pretty Garage that used to be in Diss in Norfolk theyused to be main Volvo Dealers and remember relays arent a cheap buy..always willing to help,,regards sunnyvic