OK...I'll take a shot at this one. Likely a "distant shot", but maybe worth thinking about.

Alarm.

You say behind the glove box. On a 126 and I'll bet on the 124 as well, the stock alarm system is beneath the passenger side foot well. That's "beneath" the glove box...sorta. Noises and their point of origin can be confusing.

Could this be the alarm controller yacking at you?

This suggestion may not be valid if the alarm system is the original factory unit. I want to say that the factory system would not stop the car from starting, but simply sounded an alarm in the event of dampering. Someone correct me if I'm wrong.

If your alarm is after-market, there's a much stronger possibility it could be involved here.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"

Yes, I am guilty of not troubleshooting thoroughly in the beginning. When I jumpered the fp relay pins and the pumps ran I made an assumption it was the fp relay at fault. In addition, the fp relay was original (1986) and have a reputation for failure.

Hi Guys not sure if your 86 300e is simular in electronics as my e220 but i was haveing simular problems until i replaced the OVP relay behind the battery, problem solved . cheers baz