SN95 Trouble Starting Out Of No Where

jon_95GT said:

Hey guys, ok so over the last 2 days i did both ball joints swapped them for the steeda x2s. this morning i started my car and took it for a drive to see how it felt, well i noticed on my test ride my oil temp was all the way to H and my battery wasnt charging. I got to the store cause i needed radiator fluid anyway when i came out it wouldnt start, sounded like my battery was dead, so i went in and bought one just to see maybe i drained mine from leaving the trunk open. after i installed it, the motor slowly cranked and finally started so i drove it home high oil pressure still, after i got it into the yard i shut it off and tried starting it again.. nothing dead the starter wouldnt even crank. i let it sit for about 45mins then it slowly cranked over and started. still had high oil pressure, battery still wasnt where it normally sits and the temp gauge was a little warm but nothing i was concerned about. I let it run for about 45 mins finally my oil pressure calmed down and my battery had seemed to start to charge after about another 5-10 mins i shut it off and tried to start it once again... nothing im not sure what it could be. im not sure if i knocked a ground loose while my feet where under the car or what, i do have a pretty bad exhaust leak on my passanger side where the Xpipe meets the header. any suggestions would be appricated, I have a 95 GT 5.0 it was running fine before i did the ball joins also i did one side at a time

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I'm not sure about a 95, but on a fox the ground cable drops down under the front of the engine, kind of follows the rack underneath to the passenger side of the block where it mounts. Check there (if the 95 is the same) and make sure it's tight. Check the chassis ground going to the firewall off the back of the engine, and check to make sure you don't have loose starter bolts. Mine got loose a while back and it wasn't grounding well enough to kick over.

Also- check the clamps. I had to fix my son's car the other day because corrosion built up where the cable went into the clamp on the ground, and it was acting funny.

Hot side. Just as important. Check both of the nuts on your solenoid next to the batt to make sure they are not loose or corroded. This was a problem on my sons car as well, and I wound up trashing the chinese solenoid for a borg warner. It seems the Chinese can't make a functioning solenoid.

Last but not least, hot terminal on the starter, although with the goofiness with the gauges I'm betting on either one of the major ground connections or the batt to solenoid is loose.

If none of your connections are bad, pull the starter and get it load checked. Again, I doubt that's what it is.

Edit: if you have corrosion, vinegar will eat it up like nobody's business. Use some white lithium grease or something like that to dress that connection to prevent future problems.

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.

Nothing scews with these cars more than bad grounds.

mikestang63 said:

Nothing scews with these cars more than bad grounds.

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You never heard the phrase " Why does it matter? It's just a ground.

I won't attempt to tell you how many times I have tried to educate people here on basic electricity....

jon_95GT said:

if someones doesnt think a ground matters their dumb lol it's definitely important, just look at the picture of my engine to frame ground just that wire was preventing my car from starting and when i got it to start before changing it my oil pressure and battery gauge where all messed up. put a new one in and bam runs as good as it did before


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That'll do it.

jon_95GT said:

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Yikes!