I have a 2001 Blazer 4x4 that is sprouting problems faster than I can fix them. Today, when I turned on the right blinker, I got a quick buzz from under the passenger dash, then the blinker blinked too fast. For a little while, it would buzz when I turned the right blinker on and if I turned it off then on again, it would blink. But soon after that, when I turned it on, it would just stay on. It will go off when I turn it off, and go on when I turn it on, but it won't blink. The left blinker works fine. Hazards work fine.

Also today, the brake lights are staying on all the time, including the high mount. They go off when the car is off, but are always on when the car is on.

Also today, a third (maybe related) problem appeared. When I turn the car off and remove the key, it continues to run until I take my foot off the brake.

The only remedy I've tried is to replace the turn switch relay which is located behind the glove compartment. That did not fix any of the above problems.

Oh, AND at the same time all this failed, the Service Engine Soon light came on and won't go off.

Yesterday, I had my two front tires replaced. Please tell me that replacing tires couldn't have affected the electronics like this, because that would be just too weird. But I wanted you to know everything I know.

Any ideas???

 

Get the codes scanned for that check engine light, useful clues there. Your directional: check to see if you have a bad bulb, compare the right and left to see if they look the same. Once I had a tail light go bad and the burned filament drooped onto the other filament in the bulb. It made for some *strange* diagnosing. Brake lights being on sounds like a bad brake switch on the pedal, but look to make sure the pedal arm is hitting the switch when you're not stepping on it. (out of adjustment or your brake pedal no longer rises all the way to the top for some odd reason) The running/brake pedal is, um, bizarre. By any chance do you have a remote start on the truck? I really doubt front tires have anything to do with it. All that could happen there is a damaged sensor resulting in an ABS light.

 

Thanks for responding, RonJon.

If I had a bad bulb, would the hazards still function correctly like they do?

There is no remote start for this truck.

This is so odd...all these problems arose over the course of about an hour this morning. I feel like they must all be related. This is what I get for treating the car to new tires?!?!

 

Any aftermarket equipment? Pull down the hush panel under the driver side dash and look for additional wiring/components. Typically, aftermarket electrical equipment will not be in wire loom.

It definitely sounds like someone has been messing with the wiring under the dash.

Get the codes read and let us know what they are specifically (Pxxxx).

 

We've had the car for 7 of its 8 years with no major problems. There are no after market components (manufacturer's radio, no GPS, etc.)

We try to fix things ourselves and avoid the dealer money pit, but I guess I have to visit them to get the codes which I will do early this week.

I've gotten advice to change the brake light switch (under the driver's dash). Maybe that will take care of the car not turning off until the brake is released AND the brake lights staying on all the time. Any comments on that?

This whole episode just seems so odd...that all these things could go haywire at the same time (the day after two new front tires and an alignment) and not be related. Could the alignment have triggered something in the car's computer?

Thanks for the advice.

 

A faulty ignition switch can cause your problems also. Advance or Autozone can scan for codes FREE!

 

Okay...ran to Advance Auto and the codes coming back are:

P0740 https://blazerforum.com/forum/diagnostic-trouble-codes-dtcs-49/p0740-explained-28391/
P0785 https://blazerforum.com/forum/diagnostic-trouble-codes-dtcs-49/p0785-explained-28394/
P1860 https://blazerforum.com/forum/diagnostic-trouble-codes-dtcs-49/p1860-explained-28395/

Swartlkk, you are awesomefor posting all this valuable information, but did you need to write it in Greek?!?!! This may be way over my head, but the common thread I see is a faulty ignition switch. Is there any way to confirm if my ignition switch is the culprit...before replacing it?

 

You can test the wiring (see the link in my signature). But seeing those codes, I would say that the ignition switch is a likely cause. All of those components are powered through the CLSTR fuse which is powered on the IGN 0 contact in the ignition switch.

 

Thanks for helping me narrow this down...now the big question. Is replacing the ignition switch a DIY project, or better left to a pro? Now by DIY, I don't mean YOU, who is obviously an expert...I mean someone who has never taken apart a steering column, but who has replaced a starter, door pins, brake light switch (just today). If I can do this myself, can you give me a ballpark of how long it might realistically take me?

*Combining Consecutive Posts*

I found this link with a step-by-step: https://blazerforum.com/forum/tech-articles-diy-29/ignition-switch-replacement-29167/

That airbag stuff is scary....anyway...the link has all the time estimates and it may be better to pony up 1.5 dealer hours rather than blow myself (actually my husband) into next Tuesday. Thank you for all your input. I'll let you know the outcome. If you ever get sick of that NY snow, we could sure use your expertise on the ground here in central NC!! Everyone and their cousin drives Blazers here.

 

...as does the dealer's wallet. I paid the dealer for the $90 diagnostic, and this is what the dealer says my Blazer needs:

Multi-function switch (to fix the previously mentioned problems),
Lower intake gaskets
Fuel filter
Power Steering Pump
Idler Arm

How is it the car runs, steers, and cools so well?!

I am devastated! Besides sympathy and the death of a rich relative, what I could use is your help finding the links to how to replace the above items so I can decide if I can do it myself or if I have to take out a second mortgage and let the dealership do it.