Yeah, you are low on blinker fluid.  It's a Dealer Only item, go to
the parts counter and ask for part number 1D-10T...  ;-)

*

*

 Sorry, couldn't resist.  "When it slows there is a burning smell" -
from where?  Get your nose warmed up and track it down.

 Slows down implies a voltage drop, which could be a bad wiring
connection in the circuit, either inside the flasher or in the
harness.

 If it's under the dash, it could be the flasher unit itself, which
might be from old age or defective.  That's the first thing to check,
and they are cheap to replace.

 Have someone put an ammeter inline with the flasher fuse, and make
sure there isn't a short someplace in the car wiring.  You should see
maybe 2 amps per signal light and a half amp each for the indicator
and the front side marker.  Check the lamp ratings in the lamp book to
get the draw for your particular lamps.

 On a car with a regular flasher an overload would make the signals
flash ultra fast - that's on purpose, if one lamp burns out they stop
flashing as a warning.

 But with a Heavy Duty flasher from the tow package, have an overload
and the flash rate slowing down might be the result, and one lamp
burning out will not make them stop flashing - you have to get out and
check the lamps occasionally.

 Then again, you should be doing that weekly anyway, along with
checking the fluid levels under the hood and the tire pressures.

   --<< Bruce >>--