Vehicle : '86 300E

The ABS light sometimes comes on when I hit the brake pedal and stays on. If I turn the vehicle off and then on again, it sometimes comes on and sometimes not.

I am thinking that there is something loose in the OVP or a cold solder in it making intermittant contact?

Thougts?

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1986 300E (3/2002) Rear ended and totaled (10/2009)
2000 Xterra (5/2000)
1992 400E (11/2009) -Sold
1986 300E (12/2009) - Sold
2004 E500 Wagon (6/2013) - Sold