^x2.
Been there 3x and had to replace it.
Many stories on here about it.
You will see one of those circled tabs busted off.
Hint: Don't use the crap repair part at O'Reallys, Went through 3 of those in 3 weeks before I bought the complete OEM style switch.
Like this one for my '75 (not necessarily the same as yours, I don't know the '70)
http://www.ebay.com/itm/Turn-Signal-Switch-Standard-TW-7-/221942450098?fits=Year:1975|Make:Dodge|Model:Dart&hash=item33accd07b2:g:y~gAAOSwys5WVAK5&vxp=mtr
Easy fix.
