ac diode DODGE RAM 1999 Service Repair Manual

"I" ABBREVIATION TABLE (con’t)
ABBREVIATION DEFINITION ISA Idle Speed Actuator ISC Idle Speed Control ISS Idle Stop Solenoid ITS Idle Tracking Switch IVSV Idle Vacuum Switching Valve Ign. Ignition In. Inches Inj. Injector

"J" ABBREVIATION TABLE

"J" ABBREVIATION TABLE
ABBREVIATION DEFINITION J/B Junction Block

"K" ABBREVIATION TABLE

"K" ABBREVIATION TABLE
ABBREVIATION DEFINITION k/ohms 1000 ohms (kilo as in k/ohms) kg Kilograms (weight) kg/cm Kilograms Per Square Centimeter KAM Keep Alive Memory KAPWR Keep Alive Power KM/H Kilometers Per Hour KOEO Key On Engine Off KOER Key On Engine Running KS Knock Sensor

"L" ABBREVIATION TABLE

"L" ABBREVIATION TABLE
ABBREVIATION DEFINITION L Liter(s) L/D Light Duty LCD Liquid Crystal Display LED Light Emitting Diode LH Left Hand LOS Limited Operation Strategy LT BLU Light Blue LT GRN Light Green LUS Lock-Up Solenoid Lbs. Pounds Lt(s). Light(s) Lugg. Luggage

specification .......... A .. Require repair or replacement.
Circuit shorted ......... A .. Require repair or replacement.
Connector melted,
affecting performance .. A ........... (1) Require repair or
replacement.
Connector melted, not
affecting performance .. 2 ........... ( 1) Suggest repair or
replacement.
Connector missing ....... C ............ Require replacement.
Diode open .............. A .. Require repair or replacement.
Diode shorted ........... A .. Require repair or replacement.
Insulation damaged,
conductors exposed ..... A .. Require repair or replacement.
Insulation damaged,
conductors not exposed . 1 ............ Suggest replacement.
Protective shield
(conduit) melted ....... B ........ ( 1) Require replacement.
Protective shield
(conduit) missing ...... C ............ Require replacement.
Routed incorrectly ...... B ................. Require repair.
Secured incorrectly ..... B ................. Require repair.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Voltage drop out of
specification .......... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.









\









\









\









\









\









\









\

electrical load ........ 2 ... Suggest upgrade of alternator
or removal of excess electrical
load.
Alternator's rated output
is below OEM
specification .......... B ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware non-
functioning ............ A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... (1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Diode inoperative ....... A ........... ( 2) Require repair or
replacement.
Housing broken, affecting
performance ............ A .. Require repair or replacement.
Housing broken, not
affecting performance .. .. ........ No service suggested or
required.
Housing cracked, affecting
performance ............ A .. Require repair or replacement.
Housing cracked, not
affecting performance .. 1 .. Suggest repair or replacement.
Inoperative ............. A ........... ( 2) Require repair or
replacement.
Noisy ................... 2 .. Suggest repair or replacement.
Pulley incorrect ........ B ............ Require replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Terminal resistance
(voltage drop) out of
specification .......... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Voltage drop out of
specification .......... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of OEM
specification.


ELE C TR O STA TIC D IS C HAR G E W AR NIN G - B ASIC IN FO RM ATIO N

1999 D odge P ic ku p R 1500
GENERAL INFORMATION
Electrostatic Discharge (ESD) Warning - Basic Information
All Makes amd Models
* PLEASE READ THIS FIRST *
NOTE: This article is intended for general information purposes
only.
INTRODUCTION
All Electrostatic Discharge (ESD) sensitive components
contain solid state circuits (transistors, diodes, semiconductors)
that may become damaged when contacted with an electrostatic charge.
The following information applies to all ESD sensitive devices. The
ESD symbol shown in Fig. 1 may be used on schematics to indicate which
components are ESD sensitive. See Fig. 1. Although different
manufactures may display different symbols to represent ESD sensitive
devices, the handling and measuring precautions and procedures are the
same.
Fig. 1: Sample ESD Symbol
HANDLING STATIC-SENSITIVE CIRCUITS/DEVICES

Normal Maximum Time-Out
Component Draw Draw (Minutes)
Anti-Theft System ................ 0.4 .... 1.0 ....... ...
Auto Door Lock ................... 1.0 .... 1.0 ....... ...
Body Control Module .............. 3.6 ... 12.4 ........ 20
Central Processing System ........ 1.6 .... 2.7 ........ 20
Electronic Control Module ........ 5.6 ... 10.0 ....... ...
Electronic Level Control ......... 2.0 .... 3.3 ........ 20
Heated Windshield Module ......... 0.3 .... 0.4 ....... ...
HVAC Power Module ................ 1.0 .... 1.0 ....... ...
Illuminated Entry ................ 1.0 .... 1.0 ......... 1
Light Control Module ............. 0.5 .... 1.0 ....... ...
Oil Level Module ................. 0.1 .... 0.1 ....... ...
Multi-Function Chime ............. 1.0 .... 1.0 ....... ...
Pass Key Decoder Module ......... 0.75 .... 1.0 ....... ...
Power Control Module ............. 5.0 .... 7.0 ....... ...
Retained Accessory Power ......... 3.8 .... 3.8 ....... ...
Radio ............................ 7.0 .... 8.0 ........ 15
Twilight Sentinel Module ......... 1.0 .... 1.0 ....... ...
Voltage Regulator ................ 1.4 .... 2.0 ....... ...









\









\









\









\









\









\









\


INTERMITTENT PARASITIC LOAD PROBLEMS
Intermittent parasitic lad can occur because of a memory
device that does not power down with ignition off. With an
intermittent parasitic load, battery draw can be greater than 1.0 amp.
To find and intermittent problem requires that an ammeter and
Disconnect Tool (J-38758) test switch be connected and left in the
circuit. See Fig. 1. Road test vehicle. After road test, turn ignition
off and remove key.
Monitor the milliamps scale for 15-20 minutes after ignition
is turned off. This allows monitoring memory devices to determine if
they time out and stop drawing memory current. The test switch is
needed to protect ammeter when the vehicles is started.
DIODE CHECK & SOLENOID TEST (GENERAL MOTORS)

Fig. 2: Diode Check & Solenoid Test (General Motors)
Courtesy of General Motors Corp.
QUAD DRIVER TEST (GENERAL MOTORS)

will need to shift your Lab Scope to five volts per division.
You will find that some systems have slight voltage
fluctuations here. This can occur if the injector feed wire is also
used to power up other cycling components, like the ignition coil(s).
Slight voltage fluctuations are normal and are no reason for concern.
Major voltage fluctuations are a different story, however. Major
voltage shifts on the injector feed line will create injector
performance problems. Look for excessive resistance problems in the
feed circuit if you see big shifts and repair as necessary.
Note that circuits with external injector resistors will not
be any different because the resistor does not affect open circuit
voltage.
Point "B" is where the driver completes the circuit to
ground. This point of the waveform should be a clean square point
straight down with no rounded edges. It is during this period that
current saturation of the injector windings is taking place and the
driver is heavily stressed. Weak drivers will distort this vertical
line.
Point "C" represents the voltage drop across the injector
windings. Point "C" should come very close to the ground reference
point, but not quite touch. This is because the driver has a small
amount of inherent resistance. Any significant offset from ground is
an indication of a resistance problem on the ground circuit that needs
repaired. You might miss this fault if you do not use the negative
battery post for your Lab Scope hook-up, so it is HIGHLY recommended
that you use the battery as your hook-up.
The points between "B" and "D" represent the time in
milliseconds that the injector is being energized or held open. This
line at Point "C" should remain flat. Any distortion or upward bend
indicates a ground problem, short problem, or a weak driver. Alert
readers will catch that this is exactly opposite of the current
controlled type drivers (explained in the next section), because they
bend upwards at this point.
How come the difference? Because of the total circuit
resistance. Voltage controlled driver circuits have a high resistance
of 12+ ohms that slows the building of the magnetic field in the
injector. Hence, no counter voltage is built up and the line remains
flat.
On the other hand, the current controlled driver circuit has
low resistance which allows for a rapid magnetic field build-up. This
causes a slight inductive rise (created by the effects of counter
voltage) and hence, the upward bend. You should not see that here with
voltage controlled circuits.
Point "D" represents the electrical condition of the injector
windings. The height of this voltage spike (inductive kick) is
proportional to the number of windings and the current flow through
them. The more current flow and greater number of windings, the more
potential for a greater inductive kick. The opposite is also true. The
less current flow or fewer windings means less inductive kick.
Typically you should see a minimum 35 volts at the top of Point "D".
If you do see approximately 35 volts, it is because a zener
diode is used with the driver to clamp the voltage. Make sure the
beginning top of the spike is squared off, indicating the zener dumped
the remainder of the spike. If it is not squared, that indicates the
spike is not strong enough to make the zener fully dump, meaning the
injector has a weak winding.
If a zener diode is not used in the computer, the spike from
a good injector will be 60 or more volts.
Point "E" brings us to a very interesting section. As you
can see, the voltage dissipates back to supply value after the peak of
the inductive kick. Notice the slight hump? This is actually the
mechanical injector pintle closing. Recall that moving an iron core
through a magnetic field will create a voltage surge. The pintle is

drivers. They typically require injector circuits
with a total leg resistance with less than 12 ohm.
NOTE: This example is based on a constant power/switched ground
circuit.
* See Fig. 3 for pattern that the following text describes.
Point "A" is where system voltage is supplied to the
injector. A good hot run voltage is usually 13.5 or more volts. This
point, commonly known as open circuit voltage, is critical because the
injector will not get sufficient current saturation if there is a
voltage shortfall. To obtain a good look at this precise point, you
will need to shift your Lab Scope to five volts per division.
You will find that some systems have slight voltage
fluctuations here. This could occur if the injector feed wire is also
used to power up other cycling components, like the ignition coil(s).
Slight voltage fluctuations are normal and are no reason for concern.
Major voltage fluctuations are a different story, however. Major
voltage shifts on the injector feed line will create injector
performance problems. Look for excessive resistance problems in the
feed circuit if you see big shifts and repair as necessary.
Point "B" is where the driver completes the circuit to
ground. This point of the waveform should be a clean square point
straight down with no rounded edges. It is during this period that
current saturation of the injector windings is taking place and the
driver is heavily stressed. Weak drivers will distort this vertical
line.
Point "C" represents the voltage drop across the injector
windings. Point "C" should come very close to the ground reference
point, but not quite touch. This is because the driver has a small
amount of inherent resistance. Any significant offset from ground is
an indication of a resistance problem on the ground circuit that needs
repaired. You might miss this fault if you do not use the negative
battery post for your Lab Scope hook-up, so it is HIGHLY recommended
that you use the battery as your hook-up.
Right after Point "C", something interesting happens. Notice
the trace starts a normal upward bend. This slight inductive rise is
created by the effects of counter voltage and is normal. This is
because the low circuit resistance allowed a fast build-up of the
magnetic field, which in turn created the counter voltage.
Point "D" is the start of the current limiting, also known as
the "Hold" time. Before this point, the driver had allowed the current
to free-flow ("Peak") just to get the injector pintle open. By the
time point "D" occurs, the injector pintle has already opened and the
computer has just significantly throttled the current back. It does
this by only allowing a few volts through to maintain the minimum
current required to keep the pintle open.
The height of the voltage spike seen at the top of Point "D"
represents the electrical condition of the injector windings. The
height of this voltage spike (inductive kick) is proportional to the
number of windings and the current flow through them. The more current
flow and greater number of windings, the more potential for a greater
inductive kick. The opposite is also true. The less current flow or
fewer windings means less inductive kick. Typically you should see a
minimum 35 volts.
If you see approximately 35 volts, it is because a zener
diode is used with the driver to clamp the voltage. Make sure the
beginning top of the spike is squared off, indicating the zener dumped
the remainder of the spike. If it is not squared, that indicates the
spike is not strong enough to make the zener fully dump, meaning there
is a problem with a weak injector winding.
If a zener diode is not used in the computer, the spike from

Fig. 24: Injector Bank - Known Good - Voltage Pattern
EXAMPLE #6 - CURRENT CONTROLLED DRIVER
This known-good pattern from a Ford 3.0L V6 PFI VIN [U]
illustrates that a zener diode inside the computer is used to clamp
the injector's inductive kick to 35-volts on this system. See Fig. 25.

Fig. 26: Single Injector - Known Good - Voltage Pattern
EXAMPLE #8 - CURRENT CONTROLLED DRIVER
These two known-good waveform patterns are from a GM 2.0L In-
Line 4 VIN [1]. Fig. 27 illustrates the 78 volt inductive spike that
indicates a zener diode is not used. The second waveform, Fig. 28, was
taken during hot idle, closed loop, and no load.