97 S Blazer intermittent no start

I am having another (?):uhoh: starting problem with our 97 S Blazer. It intermittently will not crank/start. When the key is inserted and turned to run the SES and other warning lights will come on, the fuel pump will cycle and then when the key is turned to start nothing happens. Cycling the key several times has to this point in time resulted in it starting but the problem seems to be happening more frequently. Last year I replaced the ignition switch because the SES, other warning lights and the fuel pump didn’t cycle when the key was turned on. Replacing the switch seemed to take care of this until this somewhat different wrinkle. Is this another symptom of an ignition switch again, :banghead: a relay or some other kind of issue?

I will presume you have the 4.3 L.

If you have a test light, find a good ground, normally I use some portion of the e-brake, and probe the yellow wire at the ignition switch while holding the switch in the crank/start position. 12 Volts ? Yes good/ No bad switch.

Since you said that the warning lights come on I will say that the fuseable link from the battery to the switch is good.

Since this is an intermittent problem I will presume fuse 20 in the instrument panel fuse block is good along with the fusable links in the circuit. Of course presuming can get one into trouble.

Next to save alot of time get 2 jumper wires with alligator clips.

Connect one end of a jumper wire to the starter solenoid terminal, small wire going to the small round cyclinder on top of the starter. Set the test light on the wiper cowling where you can see it, and connect the other end of the jumper wire from the solenoid to either end of the test light.

Take the other jumper wire and connect one end to a good ground and the other end to the remaining end of your test light.

Turn the ignition switch to the crank/start position.
If the test light illuminates bad starter solenoid.
If test light does not illuminate then:

Test the yellow if automatic, purple/ white if manual of the starter relay while turning switch to start position. This is the relay coil power from the transmission range selector or neutral safety switches.
No power here would lead me to believe that the range or neutral switch is bad.

If the above mentioned wire has power then:
Test the purple wire of the starter relay for power while turning the switch to the start position. You should have power here as this gets it's power from the battery through a fuseable link. If no power the fuseable link is bad.

If everything checks out good to this point the only remaining thing I can think of is test for continuity from the output side of fuse 20 to the input side of either your transmission range selector switch,(Automatic), or neutral safety switch,(Manual).

As I do not know your mechanical back ground please forgive me if I seemed to be talking down to you. I just wanted to try to make sure everything was clear.

Hope this helps. Dean

Had a similar problem with mine a few months back.

Go inside the passenger front wheel well, lift up the mud flap, and look at the wire connections to the starter.

If corroded, disconnect the negative battery terminal, then wire brush the starter leads to clean the corrosion off.