Hello folks... I have an '89 Fleetwood Brougham limo. It has the 5.0 Olds engine. Of course it's vin Y. Anyway, the issue is that the cruise works for anywhere between 5-20 minutes and it will just cut off. The green light indicating that the cruise is engaged will stay lit, but the cruise lets go completely and will not work. I have to turn the cruise off for about 10 seconds, turn it back on, and reset it for it to re-engage. Question is; is most likely a vacuum problem, or electrical? Is it common? Thanks in advance...