hello! ive been searching around for awhile and i figured i would try my luck here,

i have a 1980 240dl i recently bought and im having some electrical problems
when i got the car the alternator wasnt charging, i found the amp bulb wire had come disconnected from the d+ terminal, i put new connectors on it and plugged it in,

my alternator is working and i get 13.7 volts at the battery, however all my dash lights are on, but super dim

the [break failure] [parking break] [amp] and burnt out bulb light are on, but only at about 7 volts, if i pull the parking break the light is on fully bright at over 13 volts, but when i put the parking break down it goes back to a dim glow, all the lights do this, i found soon as i start the car with a charged battery they are very very dim, but brighten up after a few seconds, still a dull glow, when i give it a little gas, and bring it up to about a grand, they are so dim they are almost gone, but not always, and they brighten up with any higher or lower rpms, i checked the fuze box and replaced them all properly, and cleaned up all the connectors, i cant find whats doing this,

should i get a new voltage regulator? and a new battery?

what else can i do?

thanks guys!