a new problem has just started, last night my wife said a spark came from under the hood in the front of the motor near the alt. and after that the truck won't start. when i turn the key to the on position the radio and windows and locks work but there seems to be no power to the dash cluster, none of the light come on (brake, engine,etc.) and when i turn the key to start the truck it just cranks over but won't start.
oh as a side note the 4X4 buttons don't work neither.
97 s10 blazer 4X4

 

start by checking fuses.

 

all fuses are good, but i have no power going to the following fuses
#4- 10A-GAUGES
#5- 20A-ENG-1
#10- 20A-ECM IGN
#20- 10A-CRANK
#22- 10A AIR BAG
#24- 10A-TRANS

also when i put my foot in the brake pedal the clicking noise isn't there and i can't put it in to any gear (R,N,D).

 

All those fuses show that they should only be live with the key in the RUN or START positions. Are you sure it is in at least the run position when you are testing power?

If you are in the RUN position, you will need to check for power into and out of the ignition switch. Here are the colors and what they do: (Make sure the Red wire has at battery power) (use a Test light or DVOM to check power)

Constant 12V+ Red Ignition Switch Harness (always hot)
Starter Yellow Ignition Switch Harness (start position)
Ignition 1 Pink Ignition Switch Harness
Ignition 2 Pink/White Ignition Switch Harness
Ignition 3 Brown Ignition Switch Harness
Accessory Orange (key turned back)


I'm not sure of the key position for ignition 1, 2, or 3, but you should get power to all 3 at some point. It might not all be the same position.

 

thanks for the info, where do i check the wires from, under the dash or do i have to remove the ignition switch from the steering column. with the wires you told me to check should there be power in all the wires in the run position.

 

I'm pretty sure the only one that should not have power in the run position is the yellow (starter).

If you remove the hush panel, you will see some thick wires in a harness coming from the steering column. Just use a Test Light with a sharp point to pierce the wire to check for power. The switch will need to stay connected to the column so you can test it.

 

is this were i'm to test the wires from

 

ok i just tested the wires in the photo. the colours of the wires are as follows from the steering wheel down.

1) PINKISH PURPLE
2) ORANGE
3) BROWN
4) YELLOW
5) PINK
6) RED WITH A WHITE LINE

now i tested the wires with the key on and with the key off and this is what i found.

KEY OFF - WIRES WITH POWER
1 AND 6

KEY ON - WIRES WITH POWER
1,2,3,6

i have no power at all in 4 and 5

 

You can test right at the base of the ignition switch or at the large connector further down that harness.

*EDIT* - I was able to find a schematic that was pretty decent.

The brown (#3) wire should have power in RUN & ACCY.
The orange (#2) wire should have power in RUN.
The pink (#5) wire in RUN & START.
The pink/white wire in RUN.
And the yellow (#4) wire in START only.

Wires 1 & 6 from your description are the feeds in from the battery.

If you are not getting power to the pink wire in both RUN & START, there is a problem in the ignition switch. This wire feeds power to all of the engine management components. Without power on this wire, the engine will not start.

 

thank for the schematic i'm going back outside right now and try it again