When I try to jumpstart my 85 300D, the alarm goes off. Has anyone ever had this problem? What do you guys think I can do about it?

Thank you.

Is this the factory alarm or an aftermarket alarm? Many aftermarket alarms are triggered by disconnecting and reconnecting the battery. IMHO, you're battery is so dead that it can't keep the alarm energized. When you jumpstart, the alarm wakes up and defaults to blaring.

I don't believe factory alarms behave this way. I don't even think an 85 300D has a factory alarm.

Sixto
91 300SE
81 300SD

W124 alarm works exactly the same way if the driver's door was locked when the battery went dead -- still "thinks" the door is locked when voltage re-appears. Scared me half to death the first time it happened on the 300TE. Seems to be an antitheft system. Do no, ever, remove the radio with the alarm set and the battery disconnected (that is, lock door, remove dead battery, remove radio) or it will have to be reactivated.

Also, it sometimes goes off if you unlock the tailgate when the car was locked with the key in the driver's door.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!