98 V6 Won't Crank

Discussion in 'SN95 V6 Mustang Tech' started by Darkest of Links, Jan 18, 2014.


  1. Darkest of Links

    Darkest of Links New Member

    Joined:
    Jan 18, 2014
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    We tried jumping it and it won't work. We took out the batter and got it inspected, it's fine. We also got it charged and we cleaned the pieces connecting the battery to the car. Last night it went tiktiktik when we tried starting it but now it just goes thunk. All the electrical things like the locks, sounds and lights work until I try to start it and then it goes completely dead for about a minute. Can someone help me figure out what's wrong?
    #1
  2. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

    Joined:
    Jan 5, 1985
    Messages:
    19,555
    Showcase:
    58
    Albums:
    5
    Likes Received:
    2,386
    Trophy Points:
    174
    Try jumping the starter at the solenoid with a FRESH battery that is charged. If it still doesn't roll over then the starter is likely seized or inop.
    #2
  3. Darkest of Links

    Darkest of Links New Member

    Joined:
    Jan 18, 2014
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    is the solenoid on the starter?
    #3
  4. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

    Joined:
    Jan 5, 1985
    Messages:
    19,555
    Showcase:
    58
    Albums:
    5
    Likes Received:
    2,386
    Trophy Points:
    174
    I'm not actually sure on SN95s. Might in against the fender wall or could be a piggy back on the starter itself.

    I'm much more familiar with the Fox body. I'm sure someone will be along shortly that knows a lot more.

    Either way, it shouldn't be too difficult to find.
    #4
  5. Darkest of Links

    Darkest of Links New Member

    Joined:
    Jan 18, 2014
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    We replaced the starter/solenoid but it still won't go. When I turn the key, it goes *click* and then I lose all power for a few seconds and then it comes back on.
    #5
  6. Noobz347

    Noobz347 Stangnet Facilities Maint Tech... Er... Janitor Admin Dude

    Joined:
    Jan 5, 1985
    Messages:
    19,555
    Showcase:
    58
    Albums:
    5
    Likes Received:
    2,386
    Trophy Points:
    174
    Have you tested the motor at all? When you jumpered the starter solenoid, what was the result? Does it turn?

    Edit:
    I'm going to put a shout out to @jrichker . He likely has a checklist that will be more "on-point" than my methods of "check dis, dis, dis, go!" approach. Particularly for someone less than sure about how these systems interrelate.

    It's beginning to sound to me as if you have an ignition switch issue but I need to know what's going on over on your end. When you do something, post the results.

    The lights dimming in the vehicle when you turn the start switch to start, indicate that either the start motor is seized, or that there's a wiring/switch problem further up stream.

    This is why it's necessary to know if you tried to jumper the start solenoid and what the result (exactly) was, of that attempt.
    Last edited: Jan 19, 2014
    #6
  7. PonyGlued

    PonyGlued New Member

    Joined:
    Jan 19, 2014
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    2
    Another thing that you could look at is the battery wires...check/clean the ground to the block make sure the wire's + - are not corroded or deteriorated
    #7
  8. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,461
    Likes Received:
    338
    Trophy Points:
    134
    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. .

    [​IMG]

    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
    [​IMG]


    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
    [​IMG]


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

    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.
    #8
    SoHappeh likes this.

Share This Page