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HOMESERVICE MANUALSPLYMOUTH1984HORIZON BASE, 1.6 AREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 25 (INSTRUMENT PANEL (CONVERTIBLE))TESTINGTACHOMETER CIRCUIT TEST
1984 Plymouth Horizon Base, 1.6 A

Tachometer Circuit Test

1984 Plymouth Horizon Base, 1.6 ASECTION Tachometer Circuit Test
WARNING: This page is about a different car, the 1994 Chrysler LeBaron. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove instrument cluster. See INSTRUMENT CLUSTER  under REMOVAL & INSTALLATION. Check for battery voltage at cavity No. 8 of instrument cluster Red connector. See Fig 2 . Turn ignition on. Check for battery voltage at cavity No. 9 of instrument cluster Red connector. If battery voltage is not present at both locations, repair wiring as necessary.
  2. If battery voltage is present, check cavity No. 14 of instrument cluster Red connector for continuity to ground. If continuity is not present, repair wiring as necessary. If continuity is present, check for tachometer signal by connecting an AC digital voltmeter to ground and to cavity No. 6 of cluster Black connector. See Fig 2 .
    NOTE: PCM is located in engine compartment, near battery, and contains a 60-pin connector. See Fig 1 .
  3. A pulsating voltage reading of a minimum of one volt should be present with engine running. If voltage is correct, proceed to step 5). If voltage is less than one volt, check for wire continuity between cavity No. 6 of cluster Black connector and pin No. 43 of PCM connector. See Fig 1 and Fig 2 .
  4. If continuity is not present, repair wiring as necessary. Ensure PCM and its connector do not have damaged pins or poor connections. If continuity exists between cavity No. 6 and pin No. 43, replace PCM and retest.
  5. If all tests performed are good and tachometer is still inoperative, replace tachometer drive module. Tachometer drive module is attached to printed circuit board on rear of instrument cluster. If tachometer still remains inoperable, replace tachometer assembly.
Fig 1: Powertrain Control Module (PCM) Connector Terminal ID
G90J13507Courtesy of CHRYSLER CORP.
RENDER: 1.0x

NO RELATED

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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