Starting issue, electrical problem?

1990slow50H

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Jul 16, 2009
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Good afternoon everyone!
Ok background information- mostly stock 5.0 with manual transmission that I have owned for 20 years. Couldn’t get it started about 5 years ago, replaced starter with the mini starter off of lmr. Car started! Next time I went to start it wouldn’t fire, it sat for 2 years. Then motivation kicked back In and worked backwards and determined the solenoid on the mini starter was fried, replaced that and got one start out of it but that was it, dead again.
Last year I went through jrinkers no Start list and have looked at other threads to find the problem and solution.
So that bring me up to today, have a new silenoid for the mini starter, new motorcraft silenoid for the fender and new motorcraft ignition control module. Im not really good at troubleshooting but am good at replacing parts, does this seem like a good start? See anything I am missing? Anyone have any ideas how to remedy?

Thanks everyone for your time and help!
 
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90sickfox

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Add another ground cable from the engine to the sway bar mount by the frame rail. Can't have too many grounds. Check the ones on the engine. There should be one strap at the rear of intake ( or back of head ) to the fire wall...and one cable from the water pump on the drivers side...or the power steering bracket.
 
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General karthief

wonder how much it would cost to ship you a pair
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Ok, lets get specific, you don't state the year, that's not really important because of the forums your in, most fords starting systems are very similar for many years,
You need a good battery, good connections and good cables along with the starter. If any of them fall short in performance it will effect other things.
Is the engine spinning fast?
Does is spin fast at first then slow down.
These are symptoms, the fix may be more complex, start with checking the voltage on the cables as the engine is being cranked.
This is going with the idea that you are starting (see what I did there) with a good battery.
 
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1990slow50H

Active Member
Jul 16, 2009
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Spring Lake MI
Sorry about the lack of info, 1990. Nothing happens when the key is turned, it’s been a year but I don’t think there is even a click. Going to dig the car out of the garage next week to work on, I’ll check the cables and grounds
Thanks sickfox and kartheir
 

jrichker

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No Crank checklist for 5.0 Mustangs

Revised 05-Oct-2010 to update Fluke references.

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 both 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 .5 volts across a connection indicates a problem.

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

attachments\64167


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
attachments\21328



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
attachments\52294

Starter solenoid wiring 92-93 Mustang or earlier Mustang with upgraded high torque mini starter.
attachments\53216\


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.

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.


Typical start circuit...
Diagram courtesy of Tmoss & Stang&2birds
attachments\21328

attachment.php


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.
 
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