Need a wiring diagram for the starter solenoid. I have a 5 volt drop from battery to solenoid actuator terminal.

In the link.

https://www.google.com/search?q=2004+pontiac+grand+prix+starter+wiring+diagram

Click no start is typically a bad battery, bad starter, bad solenoid or loose dirty battery connections. But seems you have covered those items. Have you checked you negative battery cable where it attaches to the frame and motor? Use multi meter and check from positive of battery to the motor(block) for 12 volts. Also do this while turning key to start position. If voltage drops out when doing this double check battery voltage and all connections. If it does not drop then check the solenoid wire coming from ignition. When key in start position you should have a good twelve volts. If you you do then test the main leads hooked to solenoid for power. If solenoid wire from ignition has less than 12 volts double check connections at battery and also test the clutch pedal switch.

The symptom you describe sounds like a voltage drop between the starter (ignition) switch and the starter solenoid. Some causes are:
1 Faulty ignition switch - either replace or, if you're mechanically minded, try to strip the switch and clean the contacts. This is a tricky fix because these switches are not made to be serviced.
Before you go there, however, check all the connectors on the wiring harness between the ig. switch and the starter solenoid and clean them if necessary. To make sure you have a voltage drop, connect a volt meter between the battery positive and the starter pick connector, then turn the key to start position. If you measure a voltage, anything more than 1 volt, you have a problem. Another check is measure from the battery negative to the pick wire, Turn the ignition to start, and you should measure 12 volts, not less than 11 v.
Here is a quick check you can try. There are three connections on the starter motor solenoid, two heavy ones and one small one. The small one is the solenoid pick terminal. Remove the wire from this connector and connect a length of wire from the connector and touch the other end to the battery positive terminal. The solenoid should click in and the starter should engage every time you touch the battery terminal.
If this happens, you can be sure the problem is not with the starter.
If all else fails, you could fit a booster relay to the starter.
This involves mounting a relay somewhere near the starter motor. You can get a relay from a scrap yard, most modern vehicles have headlight relays which will work fine, which are mounted on the under hood fuse box. The relay should have two heavy terminals and two smaller terminals..
Run a wire from the battery positive to one of the heavy terminals on the relay, and from the other heavy terminal to the solenoid pick connector. Bring the wire that used to be connected to the pick connector and connect that to one of the small connectors on the relay. The other small connector on the relay goes to ground (any bare metal point). I hope this helps.

Sounds like the battery is weak. Yea 12 volts its good, but it needs it under the load also. Your local auto parts store Sb able to test it

If you have a relay to the starter solenoid then red one from the battery then red from the relay to the starter solenoid. The starter solenoid earth wire goes into the starter housing for the brushes if not then the red wire from the battery goes direct to the starter solenoid big terminal. The other big terminal will already got inside the housing. That takes care of the really heavy wires . The small wire goes to the little terminal between the big terminals.

Ford Excursion, Expedition, Lincoln Navigator 2000-2005
Starter

• REMOVAL & INSTALLATION
• TESTING & TROUBLESHOOTING

Print

Removal & Installation

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
   
   Negative battery cable
   
2. Raise and safely support the vehicle.
3. Remove or disconnect the following:
   NOTE To disconnect the hard-shell connector from the solenoid S terminal, grasp the plastic shell and pull off; do not pull on the wire. Pull straight off to prevent damage to the connector and S terminal.
   
   
   Starter terminal cover Terminal nut and separate the battery starter cable from the starter motor Solenoid S terminal connector, if equipped with a starter mounted solenoid
   
4. Remove or disconnect the following:
   
   Starter motor retaining bolts Starter motor from the vehicle
   

To install:

1. Install or connect the following:
   
   Starter motor and retaining bolts. Tighten the bolts to 15-20 ft. lbs. (20-27 Nm). Bttery starter cable and a terminal nut to the starter motor. Tighten the terminal nuts to 79 inch lbs. (9 Nm). Slenoid S terminal connector, if equipped with a starter mounted solenoid Sarter solenoid safety cap, if equipped
   
2. Lower the vehicle.
3. Remove or disconnect the following:
   
   Ngative battery cable
   
4. Start the engine several times to check starter motor operation.

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Remove or disconnect the following:
   
   Negative battery cable
   
3. Raise the front of the truck and install jackstands beneath the frame. Firmly apply the parking brake and place blocks in back of the rear wheels.
4. Remove or disconnect the following:
   
   Wiring from the starter motor terminals Starter motor retaining bolts, loosen Starter retaining bolts while supporting the starter motor Starter from the vehicle
   

To install:

1. The installation is the reverse of removal. Tighten the starter retaining bolts to 15-20 ft. lbs. (20-27 Nm)

4.6L, 5.4L & 6.8L Engines

1. Before servicing the vehicle, refer to the precautions section.
2. Disconnect the negative battery cable.
3. Raise and safely support the vehicle.
4. Remove or disconnect the following:
   NOTE To disconnect the hard-shell connector from the solenoid S terminal, grasp the plastic shell and pull off; do not pull on the wire. Pull straight off to prevent damage to the connector and S terminal.
   
   
   Starter terminal cover Terminal nut and separate the battery starter cable from the starter motor Solenoid S terminal connector, if equipped with a starter mounted solenoid
   
5. Remove or disconnect the following:
   
   Starter motor retaining bolts Starter motor from the vehicle
   

To install:

1. Install or connect the following:
   
   Starter motor and retaining bolts. Tighten the bolts to 15-20 ft. lbs. (20-27 Nm). Battery starter cable and a terminal nut to the starter motor. Tighten the terminal nuts to 79 inch lbs. (9 Nm). Solenoid S terminal connector, if equipped with a starter mounted solenoid Starter solenoid safety cap, if equipped
   
2. Lower the vehicle.
3. Connect the negative battery cable.
4. Start the engine several times to check starter motor operation.

6.0L Diesel Engine

1. Before servicing the vehicle, refer to the precautions section.
2. Disconnect the battery ground cable.
3. Remove starter solenoid protective cap.
4. Disconnect the starter motor electrical connections.
5. Remove the bolts and the starter.

To install:

1. Installation is the reverse of the removal procedure. Tighten the starter bolts to 18 ft. lbs. (25 Nm)

7.3L Engine

1. Before servicing the vehicle, refer to the precautions section.
2. Remove or disconnect the following:
   
   Negative battery cable
   
3. Raise the front of the truck and install jackstands beneath the frame. Firmly apply the parking brake and place blocks in back of the rear wheels.
4. Remove or disconnect the following:
   
   Wiring from the starter motor terminals Starter motor retaining bolts, loosen Starter retaining bolts while supporting the starter motor Starter from the vehicle
   

To install:

1. The installation is the reverse of removal. Tighten the starter retaining bolts to 15-20 ft. lbs. (20-27 Nm)

Testing & Troubleshooting

Feed Circuit Test

1. Make sure the battery is fully charged.
2. Disconnect the Inertia Fuel Shutoff (IFS) switch.
3. Connect a remote starter switch between the starter solenoid S-terminal and the battery positive (+) terminal.
4. Connect the Rotunda 73 Digital Multimeter positive lead to the battery positive (+) post. Connect negative lead to the starter solenoid M-terminal.
   
   

   Fig. Motor feed circuit-S-terminal (1), remote starter switch (2), battery (3), Rotunda 73 digital multimeter (4), B-terminal (5), M-terminal (6)
   

5. Engage the remote starter switch. Read and record the voltage. The voltage reading should be 0.5 volt or less.
6. If the voltage reading is 0.5 volt or less, go to the Motor Ground Circuit Component Test.
7. If the voltage reading is greater than 0.5 volt, indicating excessive resistance, move the Rotunda 73 Digital Multimeter negative lead to the starter solenoid B-terminal and repeat the test. If the voltage reading at the B-terminal is lower than 0.5 volt, the concern is either in the connections at the starter solenoid or in the solenoid contacts.
8. Remove the cables from solenoid B-, S- and M-terminals. Clean the cables and connections and reinstall the cables to the correct terminals. Repeat Steps 3 through 6. If the voltage drop reading is still greater than 0.5 volt when checked at the M-terminal or less than 0.5 volt when checked at the B-terminal, the concern is in the solenoid contacts. Install a new starter motor.
9. If the voltage reading taken at the solenoid B-terminal is still greater than 0.5 volt after cleaning the cables and connections at the solenoid, the concern is either in the positive (+) battery cable connection or in the positive battery cable itself.
10. By moving the Rotunda 73 Digital Multimeter negative lead toward the battery and checking each mechanical connection point, the excessive voltage drop can be located. When the high reading disappears, the last mechanical point that was checked is the concern. Repair or install a new connection as required.

Ground Circuit Test
A slow cranking condition can be caused by resistance in the ground or return portion of the cranking circuit. Check the voltage drop in the ground circuit as follows:

1. Disconnect the inertia fuel shutoff switch.
2. Connect a remote starter switch between the starter solenoid S-terminal and the battery positive (+) terminal.
3. Connect the Rotunda 73 Digital Multimeter positive lead to the starter motor housing (the connection must be clean and free of rust or grease). Connect the negative lead to the negative (-) battery terminal.
   
   

   Fig. Motor ground circuit-Rotunda 73 digital multimeter (1), battery (2), S-terminal (3), M-terminal (4), B-terminal (5), remote starter switch (6)
   

4. Engage the remote starter switch and crank the engine. Read and record the voltage reading. The reading should be 0.2 volt or less.
5. If the voltage drop is more than 0.2 volt, clean the negative cable connections at the battery and body connections, and retest.
6. If the voltage drop is greater than 0.2 volt, determine which way the current is flowing in the cable.
7. Connect the Rotunda 73 Digital Multimeter positive lead to the end of the cable nearest battery positive.
8. Connect the multimeter negative lead to the terminal at the other end of the cable.
9. Crank the engine and observe the voltage reading. The voltage reading should be 0.2 volt or lower. If the voltage drop is too high, clean the terminal ends. Retest, and if still high, install a new cable. If the voltage reading is less than 0.2 volt and the engine still cranks slowly, install a new starter motor.

Voltage Drop Test

WARNING When servicing the starter motor or performing other underhood work in the vicinity of the starter motor, be aware that the heavy gauge battery input lead at the starter solenoid is "electrically hot" at all times.

WARNING A protective cap or boot is provided over the battery input terminal on all vehicle lines and must be installed after servicing. Be sure to disconnect the battery ground cable before servicing the starter motor.
Always make the Rotunda 73 Digital Multimeter connections at the component terminal rather than at the wiring end connector. Making a connection at the wiring end connector could result in false readings because the meter will not pick up a high resistance between the wiring connector and the component.

TESTING WARNING
During the following test, the starter motor must not be energized for longer than 5 seconds, otherwise you run the risk of burning out the starter motor coil.

1. Remove the starter motor from the vehicle.
2. Detach the field coil lead from terminal M on the starter motor.
3. Using jumper wires, connect a 12 volt battery to the starter motor so that the negative battery terminal is attached to the starter motor housing and to solenoid terminal M, and that the positive battery terminal is connected to starter motor solenoid terminal S. The starter motor plunger should move outward; if it does not, replace the solenoid with a new one. Fig. 1: To test the solenoid plunger, first detach the field coil lead from alternator terminal M, then attach a 12 volt battery to the starter motor as shown . . .
   Fig. 2: . . . then detach the negative jumper wire from terminal M. The plunger should remain extended
   Fig. 3: Detach the other negative lead from the starter motor housing. The solenoid plunger should now retract to its normal resting position
   Fig. 4: Use an ammeter to measure the amount of current draw the starter motor uses
   
   
4. Detach the negative battery jumper wire from terminal M on the starter motor solenoid, and check the plunger for movement. The plunger should remain extended; if the plunger returns to its resting position, replace the solenoid with a new one.
5. While observing the solenoid plunger, detach the negative battery lead from the starter motor housing. The plunger should return to its normal resting position; if it does not, replace the solenoid with a new one.
6. Reattach the 12 volt battery and install an ammeter to the starter motor as shown in the accompanying illustration. The starter motor should rotate smoothly and steadily with the pinion gear moving out, and the ammeter should display less than 60 amps at 11.5 volts (Samurai models), or 90 amps at 11 volts (Sidekick, Tracker, X-90 and Sidekick Sport models). If the ammeter does not display the specified values, or if the starter motor does not operate smoothly and steadily, replace the starter motor with a new one.

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REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
2. If necessary for added under-vehicle clearance, apply the parking brake, block the rear wheels, then raise and safely support the front of the vehicle on jackstands.
3. From beneath the vehicle, label and detach all wiring from the starter motor solenoid terminals.
4. Remove one of the two starter motor mounting bolts and loosen the other bolt until it can be turned by hand, then support the starter motor with one hand while removing the last starter motor mounting bolt.
5. Lower the starter motor down and away from the engine and transmission. To install:
   
6. Hold the starter motor in position and install the two mounting bolts. Tighten the two bolts securely.
7. Reattach all applicable wiring to the starter motor solenoid. Ensure that the wiring terminals and connectors are clean and free of corrosion.
8. If necessary, lower the vehicle.
9. Connect the negative battery cable.

OK, even if you find the starter, you'll have to find a way of testing it.

Starter Testing Starting System Voltage Drop Tests NOTE: The battery must be in good condition and fully charged prior to performing this test.
There are three area of the starter motor circuits that voltage drop test can be performed on. These include:

• The starter feed circuit
• The starter ground circuit
• The starter solenoid.

Starter Feed Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of a voltmeter to the positive terminal of the battery.
4. Connect the negative lead of a voltmeter to the starter B+ terminal.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
     1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured
     2. If the vehicle uses a starter solenoid between the battery and the starter motor terminal there should be no more than 0.4 volt displayed on the voltmeter

Starter Ground Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case of the starter motor.
4. Connect the negative lead of the voltmeter to the negative terminal of the battery.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
• Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured
• Starter Solenoid
6. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
7. Verify that the vehicle will not start.
8. Connect the positive lead of the voltmeter to the case starter B+ terminal.
9. Connect the negative lead of the voltmeter to the lug (the starter M terminal) that connects the starter solenoid to the starter motor.
10. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
    • Ideally, there should be no more than 0.2 volt drop across the starter solenoid displayed on the voltmeter.

In general, there should be no more than a 1.0 volt drop throughout the entire starter motor feed and ground circuit. Any voltage drops measured in either the feed or ground circuits after connections have been cleaned will require replacement of the affected battery cable. Typically, any voltage drops measured in the solenoid are repaired by replacing the starter motor.

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Starter Relay Removal & Installation Engine Compartment Relay Box
Starter

• REMOVAL & INSTALLATION

Removal & Installation

1. Before servicing the vehicle, refer to the precautions at the beginning of this section.
2. Record the radio anti theft code data.
3. Remove or disconnect the following:
   
   Negative battery cable On 2002-05 vehicles, shift cable Starter motor electrical connectors On 2002-05 vehicles, starter heat shield Starter motor
   
   

   Fig. Starter motor mounting-3.5L Engine
   
   

To install:

1. Install or connect the following:
   
   Starter motor. Tighten the bolts to 20-24 ft. lbs. (27-33 Nm). On 2002-05 vehicles, starter heat shield Starter motor electrical connectors. Tighten the battery terminal nut to 106-141 inch lbs. (12-16 Nm). On 2002-05 vehicles, shift cable Negative battery cable Reprogram the radio anti theft codes
   

could be your starter solenoid. check that.

You can try this to verify that the starter is good or bad.


Starter Testing Starting System Voltage Drop Tests NOTE: The battery must be in good condition and fully charged prior to performing this test.
There are three area of the starter motor circuits that voltage drop test can be performed on. These include:

• The starter feed circuit
• The starter ground circuit
• The starter solenoid.

Starter Feed Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of a voltmeter to the positive terminal of the battery.
4. Connect the negative lead of a voltmeter to the starter B+ terminal.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
     1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured
     2. If the vehicle uses a starter solenoid between the battery and the starter motor terminal there should be no more than 0.4 volt displayed on the voltmeter

Starter Ground Circuit

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case of the starter motor.
4. Connect the negative lead of the voltmeter to the negative terminal of the battery.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.1 volt drop for each connection displayed on the voltmeter. No voltage should be consumed by the vehicle wiring
     1. If the battery cable connects directly to the starter motor there should be no more than a 0.2 volt drop measured.

Starter Solenoid

1. Disable the fuel system by removing the fuel pump fuse or the fuel pump relay.
2. Verify that the vehicle will not start.
3. Connect the positive lead of the voltmeter to the case starter B+ terminal.
4. Connect the negative lead of the voltmeter to the lug (the starter M terminal) that connects the starter solenoid to the starter motor.
5. Turn the ignition key to the START position and note the voltage displayed on the voltmeter.
   • Ideally, there should be no more than 0.2 volt drop across the starter solenoid displayed on the voltmeter.

In general, there should be no more than a 1.0 volt drop throughout the entire starter motor feed and ground circuit. Any voltage drops measured in either the feed or ground circuits after connections have been cleaned will require replacement of the affected battery cable. Typically, any voltage drops measured in the solenoid are repaired by replacing the starter motor.

I looked at all the steps for replacing the blower motor...they should not have messed with anything that would have affected the operation of the starter.