starter circuit related info

grumpyvette

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STARTING SYSTEM

viewtopic.php?f=36&t=520&p=645&hilit=vats#p645

Heres a collection of vats stuff to help you.

http://vats.likeabigdog.com/

http://www.thirdgen.org/vats_passkey_system

http://www.ecklerscorvette.com/catalogs ... &x=18&y=10

http://www.horsepowermonster.com/2012/s ... tion-tips/
1991fuse.png

General Information
The battery and starting motor are linked by very heavy electrical cables designed to minimize resistance to the flow of current. Generally, the major power supply cable that leaves the battery goes directly to the starter, while other electrical system needs are supplied by a smaller cable. During starter operation, power flows from the battery to the starter and is grounded through the vehicle's frame/body or engine and the battery's negative ground strap.

http://arrc.epnet.com/autoasp/framerq.asp


The starter is a specially designed, direct current electric motor capable of producing a great amount of power for its size. One thing that allows the motor to produce a great deal of power is its tremendous rotating speed. It drives the engine through a tiny pinion gear (attached to the starter's armature), which drives the very large flywheel ring gear at a greatly reduced speed. Another factor allowing it to produce so much power is that only intermittent operation is required of it. Thus, little allowance for air circulation is necessary, and the windings can be built into a very small space.

The starter solenoid is a magnetic device which employs the small current supplied by the start circuit of the ignition switch. This magnetic action moves a plunger which mechanically engages the starter and closes the heavy switch connecting it to the battery. The starting switch circuit usually consists of the starting switch contained within the ignition switch, a neutral safety switch or clutch pedal switch, and the wiring necessary to connect these in series with the starter solenoid or relay.

The pinion, a small gear, is mounted to a one way drive clutch. This clutch is splined to the starter armature shaft. When the ignition switch is moved to the START position, the solenoid plunger slides the pinion toward the flywheel ring gear via a collar and spring. If the teeth on the pinion and flywheel match properly, the pinion will engage the flywheel immediately. If the gear teeth butt one another, the spring will be compressed and will force the gears to mesh as soon as the starter turns far enough to allow them to do so. As the solenoid plunger reaches the end of its travel, it closes the contacts that connect the battery and starter, then the engine is cranked.

As soon as the engine starts, the flywheel ring gear begins turning fast enough to drive the pinion at an extremely high rate of speed. At this point, the one-way clutch begins allowing the pinion to spin faster than the starter shaft so that the starter will not operate at excessive speed. When the ignition switch is released from the starter position, the solenoid is de–energized, and a spring pulls the gear out of mesh interrupting the current flow to the starter.

Some starters employ a separate relay, mounted away from the starter, to switch the motor and solenoid current on and off. The relay replaces the solenoid electrical switch, but does not eliminate the need for a solenoid mounted on the starter used to mechanically engage the starter drive gears. The relay is used to reduce the amount of current the starting switch must carry.

Starter
TESTING
No-Load Test
With the carbon pile "OFF", make connections as shown in the accompanying figure. Close the switch, adjust the carbon pile to get 10 volts, and compare with the following RPM, current and voltage readings:
1984–87 5.7L (VIN 8) engine: No load test @ 10.6 volts — 70–110 amps, RPM at drive pinion — 6,500–10,700 rpm
1988 5.7L (VIN 8) engine: No load test @ 10.6 volts — 90 amps (max.), RPM at drive pinion — 3,300 rpm
1989–90 5.7L (VIN 8) engine: No load test @ 10 volts — 45–90 amps, RPM at drive pinion — 3,300–5,000 rpm
5.7L (VIN J) engine: No load test @ 10 volts — 45–90 amps, RPM at drive pinion — 3,300–5,500 rpm
5.7L (VIN P) engine: No load test @ 10 volts — 45–90 amps, RPM at drive pinion — 2,800–5,000 rpm
5.7L (VIN 5) engine: No load test @ 10 volts — 45–90 amps, RPM at drive pinion — 3,500–5,000 rpm
Rated current draw and no load speed indicates normal condition of the starter motor.

Fig. 1: Starter motor no-load test connections




Low free speed and high current draw indicates:
Too much friction. Tight, dirty, or worn bushings, bent armature shaft allowing armature to drag.
Shorted armature. This can be further checked on a growler after disassembly.
Grounded armature or fields. Check further after assembly.
Failure to operate with high current draw indicates:
A direct ground in the terminal or fields.
"Frozen'' bearings.
Failure to operate with low or no current draw indicates:
Open solenoid windings.
Open field circuit. This can be checked after disassembly by inspecting internal connections and tracing the circuit with a test lamp.
Open armature coils. Inspect the commutator for badly burned bar after disassembly.
Broken brush springs, worn brushes, high insulation between the commutator bars of other causes which would prevent good contact between the brushes and commutator.
Low no-load speed and low current draw indicates:
High internal resistance due to poor connections, defective leads, dirty commutator and causes listed under Step 6.
High free speed and high current drain usually indicate shorted fields. If shorted fields are suspected, replace the field and frame assembly. Also check for shorted armature using a growler.
 
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VATS anti theft

How It Works
The ignition key has a "chip" (just a resistor) installed on it, which can be easily seen. When you attempt to turn the ignition ON, the resistance of the chip is measured, and compared to the value stored in the VATS decoder module.
If they are the same, a signal is sent to the ECM telling it to fire the injectors (pin F10 for the 1227730 ECM, and pin B6 for the 1227165 ECM). At the same time, the starter enable relay will be energized by the VATS decoder module.
If the wrong resistance is read, then the signal will not be sent to the ECM, the starter enable relay will not be energized, and the injectors will not fire. Additionally, a code 46 will be shown.
This code will not be stored in the ECM's memory, and is only present while the conditions for a code 46 are present. The module will shut down for 2 to 4 minutes. During this time, any attempts to start the vehicle will not work. If the ignition switch is turned during this time, the timer will restart even if a key with the correct resistance is used.
 
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