99 Blazer 4WD not working, replaced everything

Asked by Nov 17, 2015 at 09:47 AM about the 1999 Chevrolet Blazer 4 Door LT 4WD

Question type: Maintenance & Repair

I have been fighting with my 4WD since this summer, trying to get ready for
the winter.  I've poured over countless posts and YouTube videos on it, and
I have replaced everything I can think of.  

The problem seems to be standard - after resetting the Transfer Case
Control Module (unplugging for a couple of minutes), you press the 4WD HI
button, and it flashes, the relays click, then it just reverts to 2 HI after about
10 seconds.  Do that about 3 or 4 times, and it just clicks once and goes
back to 2 HI.

I got the blink code from the TCCM initially, which showed a bad transfer
case actuator.  I replaced that, and same problem.  

I replaced the vacuum actuator underneath the battery tray.  It showed
signs of having fluid in it at one time, so I thought that might be it - nothing.  

I replaced the vacuum valve on top of the transmission.  I re-routed all the
vacuum lines coming from the vacuum valve on top of the transmission -
there are no leaks.  

I read that there was a problem with transmission fluid making it into the
vacuum system, but the other vacuum actuated valves for routing cabin air
work just fine, so there is apparently vacuum available to run valves.  

This version does not have the 4WD actuator solenoid valve like this one:
http://www.mypartsgarage.com/dorman-4wd-actuator-valve-600-104.html?
gclid=CjwKEAiAvauyBRDwuYf3qNyXmW4SJACX9-
fXEgJ8C_qsV9WKLJWY8ds_9hWwVFgV6T3Z-YW26bHusRoCYjXw_wcB

There is a vacuum resevoir in the driver side fender, which I found the
vacuum line disconnected from.  I thought AH HA!  Finally something visibly
wrong.  I reattached that, and still the same problem.  

Even though there was no corrosion, and I could hear the relays clicking,
as a last ditch effort, I replaced the TCCM.  Sure enough, same problem.  

To the best of my knowledge, it is a 100% completely new 4WD system.  
Does anyone have any idea what I could be missing?  Thanks for your
time.

3 Answers

are you aware that there is a vacuum actuator located under the battery that when 4x4 is engaged it activates the front axle i had the same issue i put the back on jack stands and engaged 4x4 and looked under and the front axle was turning but wasn't engaging into the front so id check that and also look because i noticed that when i replaced the vacuum plug on the transfer case there is a vent side and if you get dirt in that side can really mess things up

Yes, I replaced the vacuum actuator underneath the battery tray. I'll double check for any other vents, but I've replaced all the vacuum lines, so them being clogged with dirt already is unlikely.

Only other thing I can think of is if by chan5you put the vacuum hoses on wrong or if it is like mine and splits from the break booster tgere may be a problem in the line elsewhere making in not get correct vacuum

Your Answer

Add photo

Related Questions

  • Replacing 96 S10 blazer awd transmission 8 answers

    Hello, my daughters 96 Chevy blazer awd just started to lose 2nd gear. Revs real high until you let off gas and will shift. Fluid stinks to high heavan although it doesn't look bad. Can you just...

    1996 Chevrolet Blazer 4 Door LT 4WD

    -

    Maintenance & Repair

  • Electrical on 96 chevy blazer 1 answer

    My daughter bought a 96 chevy blazer. Odd battery hookup the guy had made so he could disconnect the battery when not in use. But everything worked okay. We replaced the battery, and the guys rec...

    1996 Chevrolet Blazer 4 Door 4WD

    -

    Maintenance & Repair

  • 02 Blazer Won't Start 26 answers

    My Blazer won't start. As I start to turn the key, the dash lights up, everything seems fine, but turning key to start, shuts everything off. No starter clicking, no sound, no lights at all. What I ...

    2002 Chevrolet Blazer 2 Door LS 4WD

    -

    Maintenance & Repair

  • The rear axle of my 2000 Blazer started smoking and making grinding noises. It now sits in a parking lot waiting to get worked on. 11 answers

    What is the problem and how much (approx) will it take to get it fixed?

    2000 Chevrolet Blazer 4 Door LS 4WD

    -

    Maintenance & Repair

  • why is the blazer not shifting into 4-wheel drive? 18 answers

    When the button on the Blazer is switched from, 2-wheel drive to 4-wheel, the transfer case is not shifting. why? Do u thiunk it is the switch, in the Transfer Case its self, or something else c...

    1994 Chevrolet S-10 Blazer 4 Dr STD 4WD SUV

    -

    Maintenance & Repair

Blazer

Looking for a Used Blazer in your area?

CarGurus has 1,336 nationwide Blazer listings starting at $2,000.

ZIP:

Search Chevrolet Blazer Questions

UK Questions

Are you a UK consumer? CarGurus now has a discussion forum in the UK.

Chevrolet Blazer Experts

#1 Andrew Olsen
Andrew Olsen
Reputation 1,840
#2 yetilikesbeer
yetilikesbeer
Reputation 1,110
#3 Rowefast
Rowefast
Reputation 690
View All

Related Models For Sale

Used Chevrolet Tahoe
831 Great Deals out of 28,003 listings starting at $1,700
Used Chevrolet S-10
12 Great Deals out of 1,625 listings starting at $1,399
Used Chevrolet Silverado 1500
2,584 Great Deals out of 152,652 listings starting at $1,500
Used GMC Jimmy
287 listings starting at $2,800
Used Ford Explorer
1,093 Great Deals out of 72,153 listings starting at $1,000
Used Chevrolet Camaro
415 Great Deals out of 40,745 listings starting at $3,500
Used Jeep Grand Cherokee
914 Great Deals out of 66,710 listings starting at $1,500
Used Ford F-150
3,103 Great Deals out of 209,129 listings starting at $1,200
Used Jeep Cherokee
316 Great Deals out of 54,421 listings starting at $2,495
Used Chevrolet Suburban
556 Great Deals out of 19,205 listings starting at $1,964
Used Chevrolet Impala
919 Great Deals out of 35,385 listings starting at $1,700
Used Chevrolet C/K 1500
1,061 listings starting at $1,250

Used Cars For Sale