Thanks all, I haven't had an opportunity to try any of your suggestions yet, but I will first chance.
Also, sorry about the lack of detail, it's a 1992 400E.
It's great to know what those fans are called, because I always try to find postings related to whatever problem I may be having, and only post as a last resort. This time, I was searching for radiator fans, and found nothing related. I'll now try aux fans.

Thanks again, I'll report results.

Bof