Starter or ignition switch?

[2 Sweet]

Damn, I feel like I'm posting in here almost every day lately. Help out a noob with what SHOULD be a pretty easy diagnosis (I hope)...

 

I have a 1995 S10 4.3L TBI, 2WD, 5-speed manual. When I bought the truck last month, I noticed whenever I turned the key to start, there was a very brief split second delay before it actually began to crank. Once it cranks, it fires up immediately. Every once in a while it was a little longer delay (half second maybe) but it would always start. Cool, no biggie.

 

Well over the past week there's been a few times where I try to start, and nothing happens. All dash lights remain on, when I turn the key there's ONE click (relay? It's not a repeated clicking) and the lights dim like it normally would, but it just doesn't even try to crank. It acts like my foot isn't on the clutch pedal. After 3-5 more tries, it eventually decides to fire up. Once it decides to go, it always starts quickly. Well, earlier today when I was leaving the grocery, it took about 20 tries to get it to go. By the time it decided it wanted to start, there was barely enough juice left to get it to turn over.

 

Is this the starter solenoid getting weak, or the sign of a failing ignition switch? I'm obviously not a mechanic so I'm bad with diagnosing this kind of stuff. Please help!

[Cordell]

Sounds a lot like the starter taking a shit. Most people would call that a dead spot in the starter where it has kind of burned some carbon into it effecting the clearance and resitance. Start with a starter.

[zeitgeist57]

Sounds a lot like the starter taking a shit. Most people would call that a dead spot in the starter where it has kind of burned some carbon into it effecting the clearance and resitance. Start with a starter.

 

+1. Had that same problem on one of my GM Fullsize tee-ruks. Starter it was.

 

Also, I saw pics of that S10 you got...it looks very clean. BUT, you'll want to check the charging system. If the battery cable to the starter is not in the best shape or connected properly, or the starter isn't bolted to the block well enough to ground it (or the block isn't grounded well), those can also affect the starter sequence.

 

Starter motor first. RockAuto shows NEW starter motors for $50-$100.

[Trouble Maker]

I like the direction Clay is going. It's definitely a worth taking a look over the wiring first, it can be a cheap and easy fix and you aren't just throwing parts at it. I had almost the exact same symptoms that worsened over time in an early 2000s Pontiac Sunfire. Very interment, sometimes wouldn't start a few times then suddenly started 100% OK. It ended up being the signal wire from the relay to the starter, at the starter. Where the wire was crimped into the connector (can't remember now if it was a spade or eyelet), it was fraying. So instead of there being something like 10 strands of wire connecting it, there was only a few, the finally it completely disconnected. In the diagram with the starter below, that would have been at pin 50.

 

I had tired a new relay, and probably next would have been a starter since I knew that the relay seemed to be getting it's signal to turn on just fine. Ended up being able to fix it with a part I had sitting around; new connector that was just an eyelet or spade.

 

When it happens, you can try to trouble shoot by checking the voltage going 'into' the relay, and the voltage at the starter solenoid, which is also the voltage coming 'out' of the relay.

 

Sorry if I'm going over something you already know, but I don't want to tell you to check these things and you have no idea.... plus this might help others in the future.

 

http://www.pirate4x4.com/forum/attachments/electrical-wiring/661281d1332470190-relay-diagrams-untitled.jpg

 

It's probably a 'standard' relay, I can't remember what most people call them, but the pins are marked and positioned like in the above diagram. It took me a little bit to find the starter relay in that Sunfire, I assumed it would be in the fuse/relay box, but it was off by itself on a stay somewhere near the radiator. It very well might not have the 87a (normally open) pin on the relay and/or socket. That pin (87a) is connected to pin 30 when the relay is not energized. When you send some voltage (12V DC in this case) to pin 86, it 'energizes' the relay, which is just an electromagnetic coil/solenoid. This pushes the switch and pin 87 is now connected.

 

So, to put it in simple terms. Your iginition switch sends 12V to pin 86. This connects pin 87 to 30 to send 12VDC to the starter solenoid to tell it to turn on

 

http://www.3dzubehor.com/webpics/Manualrelay2.jpg

 

So, you can see if pin 86 is getting 12V when you turn IG to 'start'. If it's not, look at something up stream of the relay i.e. iginition switch, or there could be a ton of reasons the ECU is not telling the car to turn on even though you are (the ECU can decide it's not OK to fire the engine).

Or, if that's OK you can see if you are getting 12V on pin 87, or at the starter solenoid. If you are, then it's an issue down stream i.e. starter or some of the main power wire or grounding of the starter.

[Green Bastard]

Good thoughts with checking wires. My old Camaro had this exact problem (after I put headers on it). Turned out the positive battery cable that went down to the starter had burned on the header and was arcing to the header when I tried to start it. It was a super long cable though because the previous owner had replaced it.

[2 Sweet]

Thank you for the responses everyone. I appreciate the time you guys put into your replies. Great info. I ended up replacing the starter this afternoon, and I believe that solved the problem. It now starts instantly without hesitation, I ran a few errands after replacing and so far, so good. Time will tell.

 

It's a NAPA starter, so hopefully it'll last a while.

 

Sorry if I'm going over something you already know

 

Believe me, I don't know much