Century Estate Wagon L4-151 2.5L (1985)
Diode: Technical Service Bulletins
Insolation Diodes - Replacement Information
Bulletin: 93-8-20
Date: May '93
Ref.No.: 93-130-8
Corp.Ref.No.: 178201R
SUBJECT:
INFORMATION CONCERNING REPLACEMENT OF ISOLATION DIODES
MODELS AFFECTED:
1984-93 ALL BUICK MODELS
Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which
may use such a diode are listed below:
^
A/C Compressor Clutch
^
ABS
NOTE:
The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel.
^
Wiper
^
Charging System (hidden in wire harness)
^
Parking Brake (vehicles with ABS)
^
Relays
^
Solenoids
^
Diesel Glow Plug Circuit
Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart, may be used for the applications
listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the
universal diodes listed in this bulletin.
When installing the new diode, use the following procedures to obtain a lasting repair:
1.
If the diode is taped to the harness, remove all of the tape.
2.
Paying attention to current flow direction, remove inoperative diode from the harness with a suitable soldering tool. If the diode is located next to a
connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool.
3.
Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is needed to attach the
new diode.