I have a 98 Blazer 4x4. It has the 3 button switch on the dash. I have had it in the shop twice now and they replaced all vaccum lines and accuator under the battery tray. The dang thing keeps blowing the #15 10 amp fuse! They said they checked for a short, not sure if they really checked or not, and found nothing. I have used this shop for several years now and they have always done right by me, honest and a fair price on parts and labor. I was told that my problem simply might be I need a new push button 4x4 switch... Before I dump any more money in this thing I was hoping too get opinions from others on here. When the fuse blows my battery light comes on, low fuel light, gas gauge reads empty, temp gauge quits working and gear selector light quits working... Sometimes it blows the first time I shut it off and restart it, other times it can be a day or 2 before it blows. I hardly, if ever need the 4 wheel drive where I live so that part is kinda unimportant too me. But I am sick and tired of buying 10 amp fuses!!! Any ideas would help, thanks.

 

Unplug the 4x4 3 button switch and put a fuse in, if it doesnt blow. Thats it. if not try it with other electrical 4x4 wiring parts

 

I would REALLY doubt the 4x4 switch would cause this problem. Sounds like they are using the S.W.A.G. system of diagnosis. This shop is not going to do you any further good on this particular problem - doesn't mean they are bad, just above their head.

I both agree and disagree with Newguy!! As he says, disconnect the connector from the controls. If fuse still blows, you then know the problem is not in the transfer case control part of the system (but nothing more). You would then need to look at things on the downside from SP200 which can be many!

Note these schematics are from 2001 3-button 4WD blazer so there might be minor differences. But I believe 1998 used a BCM, correct?

What I'm not understanding is how the gauges and gear selector are related to the 4WD fuse.

 

The problem with the gauges sounds like the Instrument Cluster is not communicating Class 2 serial data with the PCM for whatever reason.

Here is the check for the IC when you first turn on the keyisplay TestCertain instrument panel cluster (IPC) features are tested when the ignition is turned on in order to verify the features are working properly. The following occurs at key up:

The ABS indicator illuminates for 3 seconds .

• The AIR BAG indicator flashes 7 times.
• The Battery indicator illuminates for 3 seconds .
• The Brake indicator illuminates for 3 seconds .
• The CHECK GAUGES indicator illuminates for 3 seconds .
• The Fasten Seatbelt indicator illuminates for 20 seconds followed by 55 seconds of flashing with the drivers seatbelt unfastened or, the seatbelt indicator will illuminate for 8 seconds with the drivers seatbelt fastened.
• The GATE AJAR indicator illuminates for 3 seconds .
• The LOW FUEL indicator illuminates for 3 seconds .
• The Park Brake indicator illuminates for 3 seconds .
• The SERVICE ENGINE SOON (MIL) indicator illuminates and remains on.
• The SECURITY indicator illuminates for 3 seconds .
• The SERVICE 4WD indicator illuminates for 3 seconds .
• The SHIFT indicator illuminates for 3 seconds .
• The TOW / HAUL indicator illuminates for 3 seconds .
• All gauges sweep to the minimum physical position to the actual physical position within 3 seconds .

 

Thank you both for the reply... I will first simply try what "newguy" said and unplug the 4x4 switch and then insert a new fuse. One other thought, could a bad front passenger side wheel hub maybe be the problem? I know it is bad by the sound it is making, kind of a " rubbing " sound coming from the passenger side floor board and a slight vibration sound at any speed. The shop also confirmed it, they said it needs replaced sooner rather than later. I just don't have the money just yet for the repair... Both problems started at about the same time now that I really think about it! Any other thoughts from others are greatly welcomed, thanks...

 

I did some checking around on the Forum and seen someone simply put in a slightly bigger fuse for a stereo problem if I remember right? I am very hesitant too try that method, the 10amp is factory specific and the last thing I want is a fire or something! Worse case scenario is I can just keep buying a stash of 10amp fuses and put a new 1 in every couple days too check my gauges...

 

Let us know what you find out

 

I finally saved up the money too buy a new front passenger side wheel hub... It is going back in the shop tomorrow evening after I get off work. The goof ball truck keeps blowing the fuse though. I will report back in a few days and update the situation...

 

LOL. Then I'll give You a precious tip. Put a 12V lightbulb instead of the fuse. As, for example, You may solder two wires to the bayonet of the dead fuse and attach a lightbulb:
- If the lightbulb lights bright, You still have the sort circuit.
- If it goes glow, then it's OK.
Happy hunting. It's a proven method, not only handy, but also prevents blowing Your wallet for a new fuses

 

I am happy too report back that the #15 10amp fuse is no longer blowing! I had the front passenger side wheel hub replaced and so far that did the trick... As I stated before, the shop I use said they found no evidence of a short and by replacing that wheel hub seems too have been the problem... All gauges are working as they should and the 3 button 4x4 switch on the dash is doing just fine.