Adjust neutral park safety switch, remove console

Neutral Safety Switch

Print
REMOVAL & INSTALLATION

The back-up light switch is incorporated into the neutral/park safety switch. The neutral safety switch on 1988-94 models is mounted in the steering column.

Test/Service/Replace

The circuit on newer cars with automatic transmissions has a neutral safety, or neutral start switch installed between the ignition switch and the starter. The ignition switch cannot operate the starter motor unless the transmission is in park or neutral.
Late model vehicles with manual transmissions have a starter/clutch interlock switch that requires the clutch to be depressed to the floor.
Neutral Safety Switch
Normal operations of a neutral safety switch provides a quick check for the adjustment of the gear selector linkage.

• To do this, move the selector slowly until it clicks into the PARK position.
• Turn the ignition key to the START position.
• If the starter operates, the PARK position is correct.
• After checking the PARK position, move the lever slowly toward the NEUTRAL position until the lever drops at the end of the NEUTRAL stop in the selector gate.
• If the starter also operates at this point, the gearshift linkage is properly adjusted.
• This quick test also tests the adjustment of the neutral safety switch.
• If the engine does not start in either or both of these positions, the neutral safety switch or the gear selector linkage needs adjustment or repair.

CAUTION
Since you must work under the vehicle to adjust most shift linkages make sure you properly raise and support the vehicle before working under it. Also, wear safety glasses or goggles while working under the vehicle.
A voltmeter can be used to check the switch for voltage when the ignition key is turned to the START position with the shift lever in PARK or NEUTRAL. If there is no voltage, the switch should be adjusted or replaced.

This could be the problem. If your dash indicator is showing reverse but the transmission is in park it could be the safety switch. I'm not talking about the safety switch in the transmission though. In automatics they put a second switch to kill the starter from engaging. You need to adjust the linkage. If your shifter isn't actually on the column but the indicators are there is a cable that attaches the floor shift to the column and that is adjustable. Put the Floor shifter in Park and turn the column section nearest the dash by hand until you find park. Then adjust the cable length as needed. If all you have is the column shift it is still a cable adjustment. Set the emergency brake, drop the shifter to low 1 and adjust the cable linkage by loosening it on the transmission and manually move it all the way to low 1 then tighten it down then move the shifter to park and repeat teh adjustment process to verify that it is properly aligned. Lock the linkage back down and see if the vehicle will start, if it doesn't move the shifter to neutral and try to start the vehicle if the vehicle starts then check the column shift safety switch at the park position to make sure it is still in place and working. Typically, if the vehicle won't start in Park or Neutral it is more likely to be the Transmission neutral safety switch.

You probably need a linkage adjustment,a neutral safety switch adjustment or replacement of the neutral safety switch.

Your safety interlock switch is going out or is not adjusted properly. There is a procedure for adjusting the switch. The switch is on the transmission in the engine compartment. If you want to adjust the switch, loosen the botls holding the switch and follow steps 7-8 below. Else, you can just replace the switch entirely by following all steps.

The neutral start and backup switch are one unit mounted on the top left end of the transaxle. The neutral start portion of the switch allows electrical current to travel to the ignition system when the shift selector is in park or neutral only. The vehicle will not start when the selector is in any other gear. The backup portion operates the rear backup lamps when selector is in the reverse gear.

REMOVAL & INSTALLATION See Figures 1 and 2

1. Make sure the shift selector in the Park position, then apply the emergency brake.
2. Disconnect the negative battery cable.
3. Disengage the neutral start switch electrical connector, then remove the shift control lever on top of the switch.
4. Remove the two neutral switch attaching bolts, then remove the switch.

Fig. Fig. 1: Neutral safety switch location-vehicles equipped with automatic transaxle

Fig. Fig. 2: Adjusting the neutral safety switch

To install:

1. Install the switch on the manual shaft.
2. Loosely install the two attaching bolts and washers.
3. Insert a No. 43 drill (0.089 in.) through the hole.
4. Tighten the attaching bolts to 7-9 ft. lbs. (9-12 Nm), then remove the drill.
5. Engage the switch electrical connector, then connect the negative battery cable.

I expect the neutral safety switch within the console/shifter is coming out of adjustment or failing. You'll have to remove the trim pieces off of the console to get a good luck. Not too difficult I believe just a medium phillips screw driver will do.

Please let me know if this had assisted you.

Thanks,
Tom

The park/neutral position switch prevents the car from being started when the transmission is in any gear other than Park or Neutral.. When the transmission is in Reverse (with the engine running), the switch completes the back-up light circuit, illuminating the back-up lights.



Fig. 1: After removing the console, you can access the park/neutral position switch.

Hope help with this (remember rated this post).

Use like reference guide for GM Cadillac 1967-1989 Repair Guide Neutral Safety Switch - REMOVAL & INSTALLATION

All Except 1985-89 Eldorado and Seville
See Figure 1
The neutral safety switch prevents the engine from being started in any transmission position except Neutral or Park. The switch is located on the upper side of the steering column under the instrument panel on column shift cars, and inside the shift console on floor shift models.

1. Remove the console for access on floor shift models.
2. Disconnect the electrical connectors.
3. Remove the neutral switch.

To install:

1. Place 1967-70 column shift lever models in Drive, and 1971 and later models in neutral. Locate the lever tang against the transmission selector plate on column shift models.
2. Align the slot in the contact support with the hole in the switch. Insert a 3 / 32 in. (2.38mm) diameter pin in place. The switch is now aligned in Drive position.

1973 and later neutral safety switches have a shear-pin installed to aid in proper switch alignment so that insertion of a pin is unnecessary. Moving the shift lever from Neutral shears the pin.

1. Place the contact support drive slot over the drive tang. Install the switch mounting screws.
2. Remove the aligning pin. Connect the electrical wiring, and replace the console.
3. Set the parking brake and hold your foot on the service brake pedal. Check to see that the engine will start only in Park or Neutral.

Fig. 1: Installation of a common neutral safety switch



ADJUSTMENT
See Figure 2
1974 and later cars do not have a neutral safety switch. Instead, these cars have an interlock between the lock and the transmission selector, which is non-adjustable.

1. Place the shift lever in Neutral.
2. Move the switch until you can insert a gauge pin, 3 / 32 in. (2.38mm) diameter, into the hole in the switch and through to the alignment hole.
3. Loosen the switch securing screws. Remove the console first, if necessary.
4. Tighten the screws and remove the pin.
5. Step on the brake pedal and check to see that the engine will only start in Neutral or Park.
   

Fig. 2: Adjustment of a common neutral safety switch


1985-89 Eldorado and Seville
See Figure 3

All neutral safety/back-up light switches come with a small plastic alignment pin installed. Leave this pin in place.

1. Place the shifter assembly in the Neutral position.
2. Remove the shifter lever-to-switch nut and the lever.
3. Disconnect the electrical connector from the neutral safety/back-up light switch.
4. Remove the neutral safety/back-up light switch-to-transaxle bolts and the switch from the vehicle.

To install:

1. Position the shifter shaft in the Neutral position.

If using an old switch or the plastic pin (new switch) is broken, install a3/32in. (2.38mm) diameter pin gauge (drill bit) into the neutral safety/back-up light switch; the switch is then locked into its Neutral position.

1. Align the flats of the shifter shaft and the neutral safety/back-up light, then, align the switch-to-tang on the transaxle. Torque the switch-to-transaxle bolts to 22 ft. lbs. (30 Nm). Remove the pin gauge.
2. To complete installation, reverse the removal procedures. Make sure that the engine starts only in the Park and Neutral positions.
   

Fig. 3: Neutral start and back-up lamp switch - 1985-89 Eldorado and Seville

Hope help with this (remember rated and comment this). Good luck.

Neutral Safety/Back-up Light Switch

This is a combination switch which controls both Neutral Safety and Back-up lamp circuits.

C6 Transmission



C6 neutral start switch

1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle on jackstands.
3. Remove the downshift linkage rod return spring at the low-reverse servo cover.
4. Coat the outer lever attaching nut with penetrating oil. Remove the nut and lever.
5. Remove the 2 switch attaching bolts, disconnect the wiring at the connectors and remove the switch.
6. Installation is the reverse of removal. Adjust the switch and tighten the bolts to 55-75 inch lbs. (6.2-8.5 Nm).
7. Remove the jackstands and lower the vehicle.
8. Connect the negative battery cable.

AOD Transmission



Removing the AOD neutral start switch

1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle on jackstands.
3. Disconnect the wiring from the switch.
4. Using a deep socket, unscrew the switch.
5. Installation is the reverse of removal. Tighten the switch to 10 ft. lbs. (14 Nm).
6. Remove the jackstands and lower the vehicle.
7. Connect the negative battery cable.

4R70W Transmission




Removing the Manual Lever Position (MLP) sensor

As of 1994, the neutral safety switch is referred to as a Manual Lever Position Sensor (MLP).

1. Disconnect the negative battery cable.
2. Raise and safely support the vehicle on jackstands.
3. Disengage the harness connector from the MLP sensor.
4. Remove the 2 sensor attaching bolts and remove the sensor.

To install:

1. Install the MLP sensor and install retaining bolts. Do not tighten, the sensor requires adjustment.
2. Adjust the MLP sensor then tighten attaching screws to 80-100 inch lbs. (9-11 Nm).
3. Remove the jackstands and lower the vehicle.
4. Connect the negative battery cable.

ADJUSTMENT

C6 Transmission

1. Hold the steering column transmission selector lever against the Neutral stop.
2. Move the sliding block assembly on the neutral switch to the Neutral position and insert a 0.091 in. (2.3mm) gauge pin in the alignment hole on the terminal side of the switch.
3. Move the switch assembly housing so that the sliding block contacts the actuating pin lever. Secure the switch to the outer tube of the steering column and remove the gauge pin.
4. Check the operation of the switch. The engine should only start in Neutral and Park .

4R70W Transmission




Adjusting the MLP sensor

Park is the last detent when the manual control lever is full forward. Return 2 detents toward the output shaft for Neutral.

1. Position the manual control lever in Neutral .
2. Insert Gear Position Sensor Adjuster tool T93P-700 10-A or equivalent, into the slots.
3. Align all 3 slots on the MLP sensor with 3 tabs on the tool.
4. Tighten the attaching screws to 80-100 inch lbs. (9-11 Nm).

I hope help you. Good luck (rated this help).

1.Shifter linkage could be out of adjustment, and not allowing the Neutral safety switch to be bypassed, when in the Park position.

The shift linkage, could move the arm of the neutral safety switch far enough, to bypass it when the shifter is in Neutral, but not far enough when the shifter is in Park.

2.Perhaps the Neutral safety switch is bad, or has come loose on it's mount, and is out of position.