Volvo: 1984 240 DL wagon, locking gas cap, blinkers

Question
 I have 2 questions which I hope are easy to answer. I want to get a locking gas cap for my Volvo, but there are 2 options, Vented or non-vented. Which one do I need for my Volvo. Mine is a non Turbo. Also when my Volvo is cold the blinkers do not want to blink, Im sure its the blinker relay, but were is this located? 1 more if there is time. The rear wiper delay doesn't work. Is there a relay for this also? Thanks alot!!!  

Answer
Joey,
Non vented cap. Flasher relay is behind the left side panel by the center console. Turn on the flasher and follow the sound. Wiper relay is left floor board where the carpet meets the insulation far upper left side two relays are tucked into a small covered panel under that carpet. One is for the front and the other rear.