Now here is a invaluable tool for your Dodge product. This works on all OBDII compliant vehicles. Not only does it scan for on board error codes, display and clear them for you. But its got a full trip computer. But this one can be calibrated for your truck. The trip computer is extremely accurate! It's even more accurate than the overhead computer in a Dodge! Then as shown in the picture above you can program the gauges to display live information from the ECM/PCM. No Dodge owner should be without this good little tool!

Amazon Scan Gauge Link

Mopar's Notes:

Ok there is a few thing I see constantly asked.

Q: Can I use the fuel pressure reading on the ScanGauge II?
A: No. The ScanGauge II can only report the information provided by the PCM/ECM since there is no fuel pressure sensor or software on board the ECM there will not be a fuel pressure reading. ScanGauge II manual reports that only 10% of today's vehicles have a fuel pressure sensor!

Q: Why is the MAP sensor reading so wild?
A: There is a offset of voltage on the 1998.5 to 2002 Dodge Cummins that tends to produce this offset. I been told by 3rd Gen owners that ScanGauge II reports properly.

The starter feed circuit test (voltage drop method) will determine if there is excessive resistance in high-amperage feed circuit. For complete starter wiring circuit diagrams, refer 8, Wiring Diagrams. When performing these tests, it is important to remember that voltage drop is giving an indication of resistance between two points at which voltmeter Example: When testing resistance of battery positive cable, touch voltmeter leads to battery positive cable clamp and cable connector at starter solenoid. If you probe battery positive terminal post and cable connector at starter solenoid, you are reading combined voltage drop in battery positive cable clamp-to terminal post connection and battery positive cable. The following operation will require a voltmeter accurate to 1/10 (0.10) volt. Before performing tests, be certain that following procedures are accomplished:

• Battery is fully-charged and load-tested.
• Fully engage parking brake.
• If equipped with manual transmission, place gearshift selector lever in Neutral position and block clutch pedal in fully depressed position. If equipped with automatic transmission, place gearshift selector lever in Park position.
• Verify that all lamps and accessories are turned off.
• To prevent a gasoline engine from starting, remove Automatic ShutDown (ASD) relay. To prevent a diesel engine from starting, remove Fuel Pump Relay. These relays are located in Power Distribution Center (PDC).

1. Connect positive lead of voltmeter to battery negative terminal post. Connect negative lead of voltmeter to battery negative cable clamp (Fig. 2). Rotate and hold ignition switch in Start position. Observe voltmeter. If voltage is detected, correct poor contact between cable clamp and terminal post. Note: If equipped with a dual battery system (diesel), procedure must be performed twice, once for each battery.
2. Connect positive lead of voltmeter to battery positive terminal post. Connect negative lead of voltmeter to battery positive cable clamp (Fig. 3). Rotate and hold ignition switch in Start position. Observe voltmeter. If voltage is detected, correct poor contact between cable clamp and terminal post. Note: If equipped with a dual battery system (diesel), this procedure must be performed twice, once for each battery.
3. Connect voltmeter to measure between battery positive terminal post and starter solenoid battery terminal stud (Fig. 4). Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten battery cable connection at solenoid. Repeat test. If reading is still above 0.2 volt, replace faulty battery positive cable.
Note: If equipped with a dual battery system (diesel), this procedure must be performed on driver side battery only
4. Connect voltmeter to measure between battery negative terminal post and a good clean ground on engine block (Fig. 5). Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten battery negative cable attachment on engine block. Repeat test. If reading is still above 0.2 volt, replace faulty battery negative cable. Note: If equipped with dual battery system (diesel), this procedure must be performed twice, once for each battery.
5. Connect positive lead of voltmeter to starter housing. Connect negative lead of voltmeter to battery negative terminal post (Fig. 6). Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, correct poor starter to engine block ground contact.
Note: If equipped with a dual battery system (diesel), this procedure must be performed on driver side battery only.
6. If equipped with dual battery system (diesel), connect positive lead of voltmeter to driver side battery positive cable clamp. Connect negative lead of voltmeter to passenger side battery positive terminal post. Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten passenger side battery positive cable eyelet connection at driver side battery positive cable clamp bolt. Repeat test. If reading is still above 0.2 volt, replace faulty passenger side battery positive cable.

The voltage regulator on the 92-93 trucks is an internal unit inside the control module. If this goes out, you can mount an external voltage regulator like the earlier first gens used.

A bad crankshaft position sensor will also cause your voltage regulator to not charge the altenator. You can also get by this by doing the following:

The two terminals on the alternator for the regulator are interchangable. The alternator is a dumb alternator for an external regulator. The PCM is that regulator normally. The alternator does not care weather it is controlled by the PCM or a regulator. The PCM is not affected by not being hooked to the alternator.

The two terminal regulator has the contacts in the shape of a pyrimid. One terminal is missing. The missing terminal and one other terminal are at the base of the pyrimid.

Ok, hook the two alternator terminals to the two regulator terminals. Does not matter which goes to which. Now run a 12 volt line from an ignition source to the top regulator terminal along with the alternator wire. Thats it except you need a good ground from the alternator to the regulator case. On the 98.5 to 2002 the blue wire that is existing should be 12V keyed can be re-used for the external regulator.

A little note on this system. If you hook the 12 volt up to the wrong regulator terminal, it does fry the regulator. Not much problem, seven bucks gets another one.

The terminals for the regulator can be just the round female terminals that are used for connecters on lights and other places or go to an older junk yard and cut the plug from about any old chrysler product.

Stock charging system wiring diagram