T5 Questions

86lxhatch said:

I finally got the motor finished up, now it's on to the transmission. I bought a 4 cyl. T5 out of an 88 lx coupe. I got to drive the car first, so that was a plus. Now I have a couple questions about the (auto. to T-5) changeover...

1) I am going to use the 5 speed pedals that came from the donor car, and I read that I can use the pedals, but need to change the clutch arm? The pedals already have a UPR clutch quadrant on them that has 3 different points to which I can attach the clutch cable. Will this work, and do I really need to get a different clutch pedal arm?

I also read the changeover required parts list that I found on this site, and will be changing the bellhousing to a 302 style from a 79-93 model, and also will be going to go with the ranger diesel pilot bearing setup. Was just wondering about the pedals though...

Oh yeah, there are two electrical connections on the trans. -one on the front, right behind the bell, and another towards the tailshaft end. Which one controls the back up lights? And will it run without the neutral switch hooked up?

Thanks guys...

Click to expand...

The backup light switch is on the left side of the T5 and looks like this http://www.cjponyparts.com/product....gle&utm_medium=merchant&utm_campaign=shopping

I believe the 5 speeds will run without the neutral safety switch hooked up, I think it's the autos that won't. But I'm not 100% on that.

You said you got it out of a 4 cyl model. Will that tranny hold the power of a V-8?

Well the way i drive ill shell one in an hour... back to the drawing board.

Im running a non world class t5 as a temp. as well. It had no hookup for the nss because its so old. My car runs but I have to jump the solonoid every time. Also it will throw a code 67 and you cant pull engine running codes. however if you jump computer pin 30 to ground you can pull engine running codes. Also code 67 is known to cause surging idle. I havent noticed any odd idle though and ive been running mine for three weeks. Jumping the solonoid every time is a PITA though

The NSS does not have anything to do with the starter circuit: It is totally separate item. The no crank problem is due to a miswired clutch safety switch.

The Neutral Safety Switch plugs into a connector on top of the T5.

On the attached drawing, it is the pigtail hanging off the top cover. Item #6 on the drawing.


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. 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. .



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.


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


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.

thanks for the info jr another member on here told me that it was due to lack of a nss. And I bought into it because the problem just arose after my tranny install