What's broken on my '76 240D (115 series) to make the turn signals flash at an insane rate? All the bulbs seem to be working, though some have been recently replaced with generic auto-supply bulbs. The "flasher" looks to be some transistorized (read expensive) module. If this has gone gunny-sack, am I destined to pay big $$ for a replacement, or can I wire-in a more traditional $8 flasher unit?

Thanks!