Keep the key-to-starter circuit switching the way it should with the Standard Ignition Ignition Starter Switch US-89. It is a direct-fit replacement for the 1977-1978 Ford LTD, the 1977-1978 Mercury Grand Marquis and Mercury Marquis, the 1978 Ford Ranchero, and the Ford B-600, B-700, F-600, F-700, F-800, FT800 and FT900 trucks listed below. Its job is simple and essential: when the key turns, the switch routes power to the ignition and accessory circuits and signals the starter to crank.
Signs an ignition switch may need replacing include no crank when the key is turned to start, dash lights or accessories that cut out, or an engine that stalls intermittently. Those symptoms can have other causes, so diagnose the circuit first; if the switch is at fault, the US-89 replaces it.
Fitment:
See the Buyer's Guide tab for engine details.
Interchange: CS92 · LS303 · KS6616 · D7AA11572AA · D7AZ11572A · SW1379 · 12323017 · KS6616SB
This part cross-references / interchanges with the following part numbers:
What does an ignition starter switch do?
It is the electrical switch the ignition key operates. It sends power to the ignition and accessory circuits and signals the starter to crank when the key is turned to the start position.
What are signs the ignition switch may need replacing?
Common signs include no crank at the start position, dash or accessories losing power, or intermittent stalling. These can have other causes, so diagnose the circuit before replacing the switch.
Which vehicles does the US-89 fit?
It is listed for the 1977-1978 Ford LTD, Mercury Grand Marquis and Mercury Marquis, the 1978 Ford Ranchero, and Ford B-600, B-700, F-600, F-700, F-800, FT800 and FT900 models. See the Buyer's Guide tab for exact years.
Is this switch tested before it ships?
Yes. Standard Ignition states every switch is 100% tested to verify both its mechanical and its electrical switching performance.
What are the switch's conductors made of?
The US-89 uses copper alloy conductors, which Standard Ignition specifies for superior electrical conductivity with low resistive losses.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
