jimny bits have a trail master kit not sure on quality though here is a link for them
not cheap either though
http://www.jimnybits.co.uk/shop/trail-master-lift-kits/ford/ford-maverick-93-04-lift-kit/prod_89.html
sounds like an earth fault
i had a very similar problem in a pub about a month ago the psu was shorting the earth with the supply and giving interference