Signal Light gone haywire

My 2001 Blazer has started having odd electrical problems. The right side signal light comes on, but does not flash. The left side signal light comes on but flashes at double the normal rate like a bulb was burned out, but all the bulbs are good. Sometimes when I activate the Hazard Light switch for a few seconds, the signal light goes back to normal speed.

Also, more recently, the ABS and Parking lights will sometimes light up on the dash, unless I shut off the engine and restart. Then it all works fine. Any help would be appreciated.

The right turn signal problem may be due to a bad flasher unit. The left side problem may be a problem in the hazard warning switch. The two systems are tied together so they can effect one another.

I am not aware of any parking lights in the dash. Perhaps you mean the warning lights. If so, then I would say there may be a problem with the alternator or in the connections to it.

There is a recall on 2000 and 2001 Blazers for the multifunction switch. The Recall number is 01V364000 and the NHSTA link is:

I replaced the multifunction switch (~$200 for the part) on my 2000 Blazer a few years ago. The “Document Search” link has the installation instructions for the switch.

The dealer can use the VIN to determine if this recall was done on your vehicle. In my case the recall had been done by the previous owner so I was on the hook for the repair.

The ABS and Brake lights indicate a problem with the ABS system. If there was a problem with a sensor or wiring the lights would stay on. If it’s just a glitch, try disconnecting the battery for a few minutes to clear the ABS computer. If the light reappears then you have an ongoing problem.

One last thing, the Blazer is sensitive to battery voltage. When the battery on my Blazer was run down to 12.1 volts (25% charged), it started having driveability problems (high idle, torque converter lockup not engaging, etc). After the battery was charged to 12.6 volts (100% charge), it ran fine.

Good luck,

Ed B.

Good luck,

but all the bulbs are good

Maybe.   Does you car use the same lamp for brakes and for turn signals or parking lights?  Those multi use lamps can fail in a manor that will cause similar problems.