Paul T

My 2001 unit has a curious BRAKE LIGHT PROBLEM. When the brake pedal is depressed the CHMSL LED light(s) illuminate but ONLY the CHMSL. My "regular" brake lights do not come on.

The fuse under the hood corresponding to these lights (20A) is intact. All the bulbs (rear) ring out good. My directionals work as do my running lights.

My Haynes manual suggests the brake switch is of the single pole variety. So, I have ruled-out the switch in spite of several errrors I have noted so far in Haynes' schematics.

Has anyone dealt with this oddball electrical problem ? If so, PLEASE let me know as I am going to get stopped by the law (rightfully so) or worse.

Thanks-In-Advance

MT-2500

Haynes is not very good for a repair manual for detailed repair.
Just general coverage.
And some times will flat out lie to you about it.

You need to get a good wiring diagram and check for 12 volts into and out of brake light switch with key when the brake is pressed.
Does turn signals and 4 way flasher work right?
Post back what you find there.
A factory repair manual or a All data DIY online sub would be a big help over Haynes.
Or even your public liabary may have care repair info.
http://www.alldata.com/products/diy/index.html

__________________
Remember proper testing gives us the answer to many problems.
MT

Paul T

So then, the SPST (BRAKE SWITCH) switch depicted in the Haynes' drawing may be a "Guess" ? That it may not be a SPST....Some other switch configuration.

I know that they guessed on the current limiting resistor (510 ohms) to the LED bank because they drew it in PARALLEL to the LEDs instead of in series. The LEDs would quickly self destruct the way Haynes drew it out.

I may have a single pole double throw switch that no loger 'MAKES" on one throw (only the LED throw being still good. I'll remove it and find out.

YES, the hazzard and directionals work which I believe are the same bulb elements as the brake elements.

Any thoughts, MT ??

MT-2500

Proper testing and good wiring diagram and All data should take you threw it.

__________________
Remember proper testing gives us the answer to many problems.
MT

Paul T

Searching threads within this forum I found this GM Recall although it deals with the HAZARD SWITCH.

http://www.automotiveforums.com/vbul...t=brake+switch

From MUDDOG about three (3) resposes down from the top....

Not knowing anything about recalls and possibility of expiring. This one is the multifunction switch recall from May 2008:

http://www.allworldauto.com/recalls/...all_79799.html

Found all this BEFORE removing the BRAKE SWITCH. I need to call GM.

old_master

The stop lamp switch is a SPST N/O switch. The orange wire is HOT at all times. There are two white wires on the switched side of the stop lamp switch: One goes through a fuse and then to the trailer wiring pigtail near the rear bumper. This same wire has a spur circuit spliced to it before the fuse. It runs through another fuse and then on to the CHMSL. The second white wire at the stop lamp switch goes to the multifunction switch. The multifunction switch splits the brake and turn circuits when the turn signal switch is activated. If the white wire at the multifunction switch shows battery voltage when the brakes are applied, and the stop lamps are inoperative, the multifunction switch is faulty.

Paul T

The Brake Switch "rings-out" as being good.

Now for the last two days I have been struggling with the purchase of a MULTIFUNCTION SWITCH. Advance Autoparts stocks three (3) for my '01 Blazer.

http://shop.advanceautoparts.com/web...on%20switch___

One Borg Warner shows the Hazard Switch as being part of the assembly.

My question now is, IS THE HAZARD SWITCH TRULY PART OF THE ASSEMBLY (Multifunction) ??
I would like to go the inexpensive way and simply purchase the Hazard Switch from GM (about $20) if I can.

blazes9395

2000-01's had potential switch issues, which caused all sorts of problems. There was, as you know, a recall on these.

Here is some more info from government avaliable, public access info:
http://nhthqnwws112.odi.nhtsa.dot.go...1V364-5266.PDF

Scroll down, it gives some troubleshooting help. Hope this helps a little.

Paul T

Just to let everyone know that Friday (last) I went to a local GM dealership and they hasd in stock for $19 the following part number:

# 15174447, Switch, Hazard, Kit. I pulled out the old hazard switch and inserted the new one. When I turned on the motor my brake lights were working but I wasn't applying the brake. I shimmed the switch and with the assistance of my lovely wife, got EVERYTHING associated with the multifunction switch to operate correctly. I am not "thrilled" with the fix due to the shim job but I took the vehicle over some fairly rough terrain the last two days and the "fix" is holding fine. There is obviously a problem with the multifunction switch that mates-up with the new hazard switch I installed.

As for the recall:

I called GM' 800 number on this a week or so ago. After being on hold seemingly forever, the GM rep informed me that my vehicle was NOT part of this recall even though my Blazer (a 2001) had all the symtoms. Try as I may I could not convince her to add me to the list. Having reached the boiling point with her stonewalling and blind ascertiveness, I said good-bye. However, I am not done with them and I will post what I find with GM.

Thank-you all for your wonderful help.