When I hit the brakes my interior lighting (dash) dims, also when I turn my headlights on my left hand blimker does not blink. What does all this mean?

 

1. What are you driving?
2. Have your alternator load tested at AutoZone, etc.
3. Make sure the front left turn indicator bulb is not burned out.

 

I am driving a 1998 blazer. My turn signals work except when I turn on my headlights then the left turn signal does not blink. When I don't have my headlights on my left turn signal causes the interior dash lights to flash with the turn signal. When I press on the brake my interior dash lights dim. Turn signals seem to work fine with the headlights off and my foot off the brake.

 

Sounds like something is shorted out between the park lamp circuit and the turn signal circuit to that side. The brake and turn signal share the same filament in the bulbs at the back so I would concentrate on the rear tail light housing. Remove it and clean/inspect all of the bulb sockets.

 

Thanks for the comments, I checked the bulbs, connections and alternator. Looks like I may be searching for a short.