Another 4x4 question

2001 Chevy Blazer 4x4 4.3L

I have been trying to figure out what is going on with my four wheel drive.

The lights on the dash are not even lighting up, even after I replaced the switch.

:banghead:

3 button select-trac or 4 button auto? Have you checked both terminals of all fuses with a volt meter or test light?

3 button select-trac or 4 button auto? Have you checked both terminals of all fuses with a volt meter or test light?

its a 3 button, no i have not. Can you tell me where to find the fuse? I have looked everywhere for air lines, fuses, took the dashboard abart and I got nowhere
:banghead:

There are 5 fuses:

The first one is in the underhood fuse panel, 20amp labeled ATC.
The second one is in the instrument panel fuse panel, 10amp labeled CTSY LP fuse #8.
Both should show battery voltage at all times.

The third one is in the instrument panel fuse panel, 10amp labeled ILLUM fuse #12. This is the illumination for the switch. Should show a varying voltage depending on where the instrument lights are adjusted for.

The fourth fuse in also in the instrument panel fuse panel, 10amp labeled 4WD fuse #15. This one should show battery voltage only when the ignition is in the RUN position.

The fifth fuse is in the underhood fuse panel, (automatic transmission only) 10amp labeled BTSI. It should show battery voltage with the ignition in the RUN position and the transmission in PARK and NEUTRAL.

Check both terminals of each fuse with a test light or voltmeter. Post your results.

thank you very much, I checked everything and I found the fourth one "10amp labeled 4WD fuse #15". was blown, actually there was a 20 amp fuse in there that was blown. I replaced that and everything is working fine.

However, this fuse keeps blowing, not right away but it does keep blowing even with a 20 amp fuse in it.

What is causing this to keep happening? Is it not good to use a higher amp fuse?
Again thank you for the help it is greatly appreciated :smile:

That fuse feeds a brown wire that runs from the fuse, directly to the switch on the dash, with no connectors in between. Are you operating the switch when the fuse blows? If so, what button are you pushing?

Using a higher amp fuse will cause the wiring to heat up and possibly melt other wires. Only use the correct amperage fuse.

That fuse feeds a brown wire that runs from the fuse, directly to the switch on the dash, with no connectors in between. Are you operating the switch when the fuse blows? If so, what button are you pushing?

Using a higher amp fuse will cause the wiring to heat up and possibly melt other wires. Only use the correct amperage fuse.


In the past the fuse light on the dash would just "go out" or the fuse would just blow without touching anything though.
It hasen't blow since I replaced the switch (so about 5 min is all), so I will just have to wait and see. If the fuse keeps blowing so you think that replacing that wire should solve the problem? or any other suggestions...thanks again

There is a short somewhere, it could be most anything, not necessarily the brown wire. Keep an eye on it and notice what was going on when it blows. It's possible it was the switch, too early to tell.

There is a short somewhere, it could be most anything, not necessarily the brown wire. Keep an eye on it and notice what was going on when it blows. It's possible it was the switch, too early to tell.

Thank you very much for your help

Hi im having the same problem as you with an identical vehicle, my fuse keeps blowing (number 15 one) everytime i put it into drive and take my foot off the brake. If you could give me some idea of what to look for next it would be greatly appriciated. Thanks.

Hey,
Unfortunately, I have not gotten to the bottom of why my fuse keeps blowing. Mine doesn't blow when I take my foot off the brake, it blows when I shut the vehicle off, when I turn it back on its blown.

When I need to use the 4wd I just put a fuse in. It's frustrating and I don't want to take it to a shop so hopefully, eventually when I get some time and a good piece of advice, I can just fix it.

If I fix it I will let you know what worked, and please if you do let me know. Thanks