Many car owners searching for the diagnostic port on a 1987 Oldsmobile Delta 88 might be looking for the OBD2 location. However, vehicles from 1987, including the Oldsmobile Delta 88, predate the widespread adoption of OBD2 (On-Board Diagnostics II) systems. Instead, your 1987 Delta 88 is equipped with an earlier OBD system, often referred to as OBD1 or ALDL (Assembly Line Diagnostic Link). Understanding this difference is key to diagnosing any check engine light issues you might encounter.
Understanding OBD1 in Your 1987 Oldsmobile Delta 88
The transition to OBD2 as a standardized diagnostic system in vehicles was a gradual process. In 1987, automotive technology was different, and diagnostic systems were less sophisticated than what we see today. The 1987 Oldsmobile Delta 88 utilizes an OBD1 system. This means you won’t find the standard 16-pin OBD2 connector that is commonplace in vehicles from the mid-1990s onwards.
Locating the ALDL Connector on a 1987 Oldsmobile Delta 88
To access the diagnostic information from your 1987 Oldsmobile Delta 88, you need to locate the ALDL connector. This connector is typically a 12-pin connector and is often found inside the passenger compartment.
Here’s where to look for the ALDL connector in your 1987 Oldsmobile Delta 88:
- Under the dashboard: The most common location is beneath the dashboard on the driver’s side. You might need to look around the steering column area and towards the center of the dash.
- Center Console Area: In some cases, it may be located near the center console. Check under the dash, close to the radio or climate controls.
The ALDL connector is usually a rectangular black or gray plastic connector. It is not as prominent or easily visible as the OBD2 port in modern cars, so you might need to look carefully.
Once you locate the ALDL connector, you’ll be ready to retrieve the diagnostic trouble codes.
OBD1 ALDL connector location on a 1987 Oldsmobile Delta 88 for reading check engine light codes. Jumper wire connection points are highlighted for accessing diagnostic information.
Reading OBD1 Codes on Your 1987 Delta 88 Without a Scanner
Unlike OBD2 systems that require a scan tool to read codes, you can retrieve OBD1 codes on your 1987 Oldsmobile Delta 88 using a simple jumper wire and by observing the check engine light flashes.
Here’s how to read the codes:
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Locate terminals A and B on the ALDL connector. These terminals are usually labeled or can be identified based on diagrams available online or in repair manuals for your vehicle.
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Use a jumper wire to connect terminal A to terminal B. A simple piece of wire with stripped ends will work.
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Turn the ignition key to the “ON” position, but do not start the engine.
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Observe the “Check Engine” light. The check engine light will begin to flash a series of codes. These are two-digit codes.
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Count the flashes. The codes are displayed as a series of flashes, separated by pauses. For example, code 22 would be displayed as two flashes, a short pause, then two flashes again. Codes are typically repeated three times. The sequence usually starts with code 12 (flash, pause, flash-flash), which indicates the system is in diagnostic mode.
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Record the codes. Write down all the codes you observe.
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Consult an OBD1 code chart. Once you have the codes, you’ll need to look up what they mean. OBD1 code charts for GM vehicles of this era are readily available online. These charts will tell you the fault associated with each code.
By following these steps, you can effectively diagnose the cause of your check engine light illuminating on your 1987 Oldsmobile Delta 88. Remember to consult a repair manual or online resources for the specific OBD1 code definitions for your vehicle to accurately troubleshoot the issue. While your classic Delta 88 doesn’t have OBD2, understanding its OBD1 system is crucial for effective maintenance and repair.
