HELP? NO START!

[blkstng]

I have a 2003 GT, so i have been having this no start problem for a while its wierd cause it kinda just does it when it wants other times it fires right up and runs perefect! but when this happens i turn the key all the way and there is no fire the starter doesnt engage and turn over. so i check it by jumpering it from the solenoid control wire to the power and it started, so from there i checked my ignition relays for continuity and to make sure they clicked by putting power to them with a battery and they are good to, after that i checked my clutch pedal position sensor for continuity which is really hard to get at when depressed it is supposed to make continuity so i just shorted out the two leads on the other end of the connector to simulate the sensor making continuity to se if it would start and if it did then it would have been that sensor but it didnt start so after that i took out the ignition switch and checked all positions on that for continuity and they were all good. Now i have no idea what to do or check im going to go through it all again and check it again but im not sure what else to do if someone else on here has had experience with problems like this it would be great to hear from you or if you have good ideas or suggestions for me PLEASE let me know and fill me in cause this is a real nuisance problem thanks!

[kineda]

ground issue?

[CleanLX]

Battery cables tight?

[blkstng]

Battery cables are good. Grounding issue? I don't think so is there a positive way to check for one or a good way to to diagnose it?

[iamtheshaner]

Do you have good power at the starter control circuit? Just because you jumped the power cable to the solenoid doesn't mean you are getting good power to the S terminal. I assume you are verifying continuity using a DVOM? If you are simply "ohming" out your wires between the ignition switch and the S terminal this isn't adequate. You need to put a load on the circuit. See if you can light a bulb with it. A 12v reading at the S terminal in the "start" position WITH THE S TERMINAL CONNECTED is another good way to see if you are getting a voltage drop across the control circuit. An open circuit voltage test is no more effective than a continuity test.

If your ignition switch, clutch switch and starter relays are good (swap them with another known good like your horn and retest) AND the starter works when jumped - I'd be chasing down my S terminal power.

[ef5]

Battery cables are good. Grounding issue? I don't think so is there a positive way to check for one or a good way to to diagnose it?

Is it a side post? Sometimes the terminals rust on the inside that you can't see until you screw them out.

[blkstng]

no my battery is not a side post and they are not rusted car is inside year round and well takin care besides this BS problem. Yes i am using a digital multi meter and i was ohming out the components. Maybe you could kinda guide me through this S terminal power test? I would like to try it but have not ever done this before so i dont quite know what to do exactly.

Does anyone think that if i towed it into ford and had them hook it up to there i think its called "IDS" computer if it would let me know whats wrong i know its kinda expensive and might not garuntee me anything but im just wondering?

[iamtheshaner]

The IDS is the Ford scan tool and you are looking at about $75 just for them to diagnose the problem. This may be your best option but frankly, I wouldn't bring it in unless this is completely over your head.

To test the S terminal (this is the thin wire white with a pink stripe) you will need to put the red lead of your DVOM on this terminal with the wire connected. Put the black lead of your DVOM on battery negative. DO NOT DISCONNECT THE WHITE/PINK WIRE DURING THIS TEST. You should have 12v on this wire when you turn the key to the "start" position. If you have less than 12v - there is resistance in the circuit. Look for corroded terminals, exposed wire frays, corroded relay terminals, etc.

If you have 0v on this wire, the relay is not being activated, there is an open in the wire to the relay box, the relay itself is bad, or the fuse that powers the relay is open (fuse 1.3, 40A in the underhood box). If the fuse is blown, there is a short to ground somewhere between the fuse and the starter motor. Look for signs of water contamination in the underhood fusebox.

If the engine cranks when you jump the starter (jumping power from the fat red cable to the white/pink wire) your battery terminals are fine, the starter motor is fine and your battery power cable from the battery to the starter is fine.

OR

jump terminals 30 and 87 of the relay. This should cause the engine to crank and it will prove out all mentioned above. If this works, you have an issue from your ignition switch to the relay.

[blkstng]

Hey thanks 90lxhatch this is the best input i have had so far out of all the mustang forums im going to try this today. What would you say/think if when i do the test and it turns out to be good that i have a good 12v?

[iamtheshaner]

I realized that i left out some info. Post was updated.

If you have a good 12v at the S terminal in the "start" position the starter should work. When you "jumped" the starter you provided a known good 12v to this terminal.

Your issue is intermittent which tells me you likely have a loose or corroded connection somewhere.

[blkstng]

Yes that makes sense i guess that might be why i didnt know what you were telling me its just another way to test it tho and im still gonna do it (the s terminal test) but i get it i shouldnt have to do it. So whould you say i should check all connections and follow everything through and back on the ignition starting and chraging system circuit?

[iamtheshaner]

Yes that makes sense i guess that might be why i didnt know what you were telling me its just another way to test it tho and im still gonna do it (the s terminal test) but i get it i shouldnt have to do it. So whould you say i should check all connections and follow everything through and back on the ignition starting and chraging system circuit?

If i understand what you are asking, no. What you need to isolate is if the starter won't engage because the S terminal power is crap OR if the control side of the relay (the part your ignition switch provides power to) is bad.

Jumping the relay or checking the power at the S terminal will isolate your issue. If jumping the relay allows it to crank - you need to see where you are losing power between the ignition switch and the relay.

[blkstng]

so ill check my S terminal again then ill check this relay, is it one of the relays located in the fuse box under the hood? or is it under my steering column neer the ignition switch somewhere? i have checked the relays in my fuse box is why i ask. also how woud i jumper a relay or are you talking about jumping the S terminal? i think were on the same page im just a little confused this is a shitty problem! by the way thank you for you patients and telling me all this!

[iamtheshaner]

so ill check my S terminal again then ill check this relay, is it one of the relays located in the fuse box under the hood? or is it under my steering column neer the ignition switch somewhere? i have checked the relays in my fuse box is why i ask. also how woud i jumper a relay or are you talking about jumping the S terminal? i think were on the same page im just a little confused this is a shitty problem! by the way thank you for you patients and telling me all this!

Your underhood fuse box should have 5 relays in it. Two small ones and three big ones. Your starter relay is a big one - the one in the middle. Pull it out, and you will see 4 or 5 terminals. The terminals you want to jump will be angled 90* different and opposite one another. Make sure the car is in neutral when you do this and try to use a decent jumper wire, I would advise against a paper clip.

l--l jump this one

[] [] These two terminals are the control side of the relay.

[] to this one

[blkstng]

i have pulled those relays and used another battery to jumper for power before and they clicked and when they did you should get continuity across the control side of the relay i beleive i dont remember i did it the same as the book told me to the and there was continuity which leads me to believe that they are good?