My 1994 chevy lumina car has a blinker problem. The right blinker and rear lights work fine. The left blinker does not light up or blink on the instrument panel and the rear lights won't flash unless I hold the lever down slightly. If I pull the lever down to the lock position, it does not blink or light up on the instrument panel and the rear lights stay lit and do not flash. Is this problem the flasher or the turn siganl switch?

You obviously have a bad connection somewhere in the taillight. Some trucks it is a common problem and the taillight circuit board is the problem.

It could be a bad multifunction (turn signal) switch. The way that switch works, it is possible that it can turn on the front blinker and not the rear one. It also cancels the brake circuit so the turn signal can work with the brake pedal depressed.

However, a more likely cause would be a break in the YELLOW/BROWN wire at the rear of the truck. It is common for the connector to get corroded at the left rear frame area where the bed harness connects to the vehicle harness. If you have trailer connections spliced into the wiring harness, these connections are also prime candidates for corrosion. I would look there first. Inspect these harnesses thoroughly all the way up and into the tail light assembly.

If the wires under the back of the truck look good, then I would check for power coming out of the turn signal switch. The wire at the turn signal switch is plain YELLOW (with no brown tracer). It is Pin (M) on the turn signal switch connector. The front signal is a LIGHT BLUE wire at the turn signal switch Pin (H). If you probe these with a test lamp, they should both work the same except the yellow wire will be hot with the brake pedal depressed and the switch NOT in the left turn position. If there is no power at the switch connector, replace the switch.

yes, on multiple electrical problems like this the first thing is to check the ground circuits, in you case focus on the left rear

first repair the ground to the right rear light, as for the heater it may be a switch or a bad contact

make sure our lights at rear are grounded sounds like a bad earth

Sounds like wrong bulbs in some sockets

the rapid blink is because there is a bulb outage some where, Pull Over turn on left Blinker Get out of your car look at the front left blinker hen walk to the rear of your car and look at the left rear Blinker light then do the same for the right side blinkers if all are working rapidly your left right switch is bad

any increase in bink speed is direcly related to a bulb being burt out.

Usually a fast turn signal means that there is a light out. You should probably check all of your lights, including back-up lights, and turn signals. If there is one out then replacing the burnt out bulb should fix the problem.

The problem could be the wiring connecting to the lights, you need to check them for bare wires. Look them through for any metal hanging out of the rubber insulation. You may need to get new wiring.