94 Gt, Manual, No Start Issue....woot!

[Joe117]

Incoming wall of text...

I was having an issue with my mustang not wanting to crank. Power would dim inside and I didn't have enough to crank the car. This has happened a couple of times and I just replace the battery and go on my merry way. I have been cheap in the battery replacements, so I figured the once a year bit was that. When this would happen, I would just wiggle my positive and negative wires around for a little bit and then I would be able to crank the car and get it to where I needed to go. This last time, I decided to get a little better battery and not have to replace it so soon. About a week later, I had this issue again. It became more difficult to coax it to start. I figured that I had some bad or corroded connections along my battery cables. I took it to a mechanic to replace those along with an Stabilizer Bar Bushing (who really wants to jack up a mustang and crawl around underneath for all that?). The mechanic takes a year and a day (figuratively speaking of course) to replace the parts. The car gives him a little trouble starting, but cranks right up. On the drive home, I notice no odd gauge readings. Everything seems normal. I stopped at a gas station to get a drink, came back out and the car would not start. This is where my no start issue happens.

I get decent power inside. Once I turn the key, I hear the fuel pump engage and then I hear one click from the starter then the power levels go down a hair. Nothing else happens. We were able to push start the car. I drove it to a friends house without issue. At the friends house we jacked the car up, pulled the starter and had that tested. It tests green. I replaced the starter relay in the fuse box. We tried jumping the car to test the battery. Still nothing. Tapping on the starter with a wrench did nothing either. We checked the grounds (which the location of the main one seems incredibly stupid btw). We ran a cable from the battery directly to the starter and tried to start and got nothing but sparks (anyone want to do some welding?). We used a wire brush on a part of the engine and fire wall and ran a new ground. Still nothing.

At this point, it is Sunday and I have no idea where to go from here. The mechanic I used is closed today along with my normal mechanic. Any help or ideas would be greatly appreciated. I plan on calling both Monday morning.

Quick Reference for Problem:

1) Initial Starting Issue, Wiggle Battery Wires to Start.
2) New Battery. Things Run Great.
3) Week Later - Problem Returns, Wiggling does not work as well.
4) Mechanic Replaces Battery Cables and Stabilizer Bar Bushing.
5) Car Starts and runs.
6) Car gets turned off, will not turn back on. Power + one click from starter then nothing.
7) Push started, runs fine.
8) Starter Relay replaced.
9) Starter pulled and tested. Tests Green.
10) Tapped on Starter, still nothing.
11) Car jumped, still doesn't want to start.
12) Grounds checked, all look ok.
13) Wire ran from battery to starter, sparks but no start.
14) New ground ran from motor to firewall.

Bonus:
Thought it could be an issue with the clutch sensor. If the clutch is not depressed, I do not get the click from the starter. I believe that is working as it is supposed to.

Alternator has also been tested before and it tests green.

 

[Chythar]

Did you have any issues when the car ran? I had similar issues, but I got an occasional stutter while driving. Turns out I completely forgot to check the cap & rotor on the distributor, and the contacts were corroded. Replaced them and the car ran like new.

As for the clutch sensor, you are correct. The engine will not crank unless the clutch pedal is pushed to the floor.

 

[Joe117]

I did not have any issue while it was running. I have replaced the cap and wires before, but I guess it wouldn't hurt to give that a look.

 

[jozsefsz]

Since you ran a wire from the battery straight to the starter, and it didn't move, I'd suspect... the starter. Could be an intermittent short or heat-related problem with it or the solenoid that didn't show up on the bench test. Also check the thin wire to the solenoid, those will often corrode right off of the post (if it's clicking that's less likely). A heavy current draw (lights dimming) but no starter action tells me the starter's fried inside.

 

[Joe117]

I did check that thin wire. It was corroded badly at the connection. We stripped it and put a new one on. There is a heavy current draw, lights do dim and I can watch my battery gauge drop a couple volts. If I understand you correctly, you are telling me that the issue may be with the solenoid and not the starter. The bench tests does not test the solenoid? Is there another way to test the solenoid?

 

[jozsefsz]

The solenoid is attached to the starter, so a bench test will check it too (though the starter itself is not under much load typically, and it's usually nice & cool as well, so a bench-test is pretty half-assed when it comes to starters). I think your starter has crapped out, it's just not showing up on the bench-test since it's an intermittent problem. The whole assembly's about $60 on RockAuto (Starter+Solenoid).

 

[Joe117]

Looks like I have a few things to do tomorrow. I'll be sure to update this thread.

 

[Joe117]

Took care of everything today. Checked the cap and wires, they were ok. Replaced the starter and was still having the issue. Ran voltage tests on it and it was fine. Was able to get a hold of the mechanic that originally did the work. I pushed started the car and got it to him. Apparently there was a "short" somewhere along the battery cable that he installed. He also decided to buff a part of my bumper and put a small clear coat of paint on a section to "show me how good it would clean up." Needless to say, I am not going back there again...not even to have the oil changed. Thanks for everyone's ideas. I appreciate it.

 

[jozsefsz]

Sorry you ended up needlessly replacing the starter, but you mentioned that you jumped a wire straight to the starter and it still would not turn over, which would have eliminated the short in the wire as a problem. The advice you receive is only as good as the information you provide. I'm glad you're sorted out now.

 

[OVAL BLUE]

I had same problem with a Ranger. Bad ground connection. I have also experienced this with 120/240V. There are sometimes multiple large frame/battery/negative connections, find them all and eliminate them as culprits . Don't judge any electrical connection by visual appearance, take it apart and inspect it ,especially low voltage, No guarantees that will fix I, but any electrical system has to have a good ground to operate
Keep digging, you'll find it..

When you run a jumper it is usually the positive. To eliminate the Neg side as an issue, with positive jumper in place (Batt Pos to Starer), jump from Neg Battery terminal to motor block,
Check back, noise or no noise.

 

[jrichker]

No Crank checklist for 5.0 Mustangs

Revised 24-Oct-2013 to update voltage drop figures.

No crank, slow crank and stuck starter solenoid problems have the same root causes – low battery voltage and poor connections. For that reason, they are grouped together.
Use the same initial group of tests to find the root cause of slow crank, no crank and stuck solenoid problems.

Since some of the tests will bypass the safety interlocks, make sure that the car is in neutral and the parking brake is set. Becoming a pancake isn’t part of the repair process…

1.) Will the car start if it is jumped? Then clean battery terminals and check battery for low charge and dead cells. A good battery will measure 12-13 volts at full charge with the ignition switch in the Run position but without the engine running.
A voltmeter placed across the battery terminals should show a minimum of 9.5-10 volts when the ignition switch is turned to the Start position and the starter engages or tries to engage. Less than this will result in a clicking solenoid, or slow cranking (if it cranks at all) or a starter solenoid that sticks and welds the contacts together.

Most auto parts stores will check your battery for free. It does not have to be installed in the car to have it checked; you can carry it with you to the auto parts store.

The battery posts and inside of the battery post terminals should be scraped clean with a knife or battery post cleaner tool. This little trick will fix a surprising number of no start problems.

The clamp on with 2 bolts battery terminal ends are a known problem causer. Any place you see green on a copper wire is corrosion. Corrosion gets in the clamped joint and works its way up the wire under the insulation. Corroded connections do not conduct electricity well. Avoid them like the plague...

If the starter solenoid welds the contacts, then the starter will attempt to run anytime there is power in the battery. The cables and solenoid will get very hot, and may even start smoking. The temporary fix for a welded starter solenoid is to disconnect the battery and smack the back of the solenoid housing a sharp blow with a hammer. This may cause the contacts to unstick and work normally for a while.


A voltmeter is handy if you are familiar with how to use it to find bad connections. Measure the voltage drop across a connection while trying to start the car: more than .25 volts across a connection indicates a problem. The voltage drop tests need to be done while cranking the engine. It's the current flowing through a connection or wire that causes the voltage drop.

See http://assets.fluke.com/appnotes/automotive/beatbook.pdf for help for help troubleshooting voltage drops across connections and components. .

Voltage drops should not exceed the following:
200 mV Wire or cable
300 mV Switch or solenoid
100 mV Ground
0.0V Connections
A voltage drop lower that spec is always acceptable.

2.) Check the battery to engine block ground down near the oil filter, and the ground behind the engine to the firewall. All grounds should be clean and shiny. Use some sandpaper to clean them up.

3.) Jump the big terminals on the starter solenoid next to the battery with a screwdriver - watch out for the sparks! If the engine cranks, the starter and power wiring is good. The starter relay is also known as a starter solenoid.

The rest of the tech note only concerns no crank problems. If your problem was a stuck solenoid, go back to step 1.

4.) Then pull the small push on connector (small red/blue wire) off the starter solenoid (Looks like it is stuck on a screw). Then jump between the screw and the terminal that is connected to the battery. If it cranks, the relay is good and your problem is in the rest of the circuit.

5.) Remember to check the ignition switch, neutral safety switch on auto trans and the clutch safety switch on manual trans cars. If they are good, then you have wiring problems.

Typical start circuit...
Diagram courtesy of Tmoss & Stang&2birds

6.) Pull the starter and take it to AutoZone or Pep Boys and have them test it. Starter fails test, then replace it. If you got this far, the starter is probably bad.


Starter solenoid wiring for 86-91 Mustang

Starter solenoid wiring 92-93 Mustang or earlier Mustang with upgraded high torque mini starter.

Electrical checks for the switches and starter solenoid

Remove the small red/blue wire from the starter solenoid. Use a screwdriver to bridge the connection from the battery positive connection on the starter solenoid to the small screw where the red/blue wire was connected. The starter should crank the engine. If it does not, the starter solenoid is defective or the battery lacks sufficient charge to crank the engine.

If the starter does crank the engine, the problem is in the clutch safety circuit (5 speed) or Neutral Sense Switch (auto trans) or ignition switch.


See the Typical start circuit diagram above for wiring information for troubleshooting.

You will need a voltmeter or test lamp for the rest of the checks. Connect one lead of the voltmeter or test lamp to ground. The other lead will connect to the item under test.
Look for 12 volts on the white/pink wire when the ignition switch is turned to the Start position. Check the ignition switch first.
No 12 volts, replace the ignition switch.

The next step will require you to push the clutch pedal to the floor (5 speed) or put the transmission in neutral (auto trans) while the ignition switch is turned to the Start position.
Good 12 volts, check the clutch safety switch (5 speed) or Neutral Sense Switch (auto trans) for good 12 volts on both sides of the switches. No 12 volts on both sides of the switch and the switches are defective or out of adjustment. Check the wiring for bad connections while you are at it.