Welcome to the site from California!have a question about a choke light operation on a 86 Chevy crk# 931 coming from cluster should their be power coming from dash with key on theirs already power at crk# 350 coming from fuse box just trying to make sure its working properly....
Ckt 931, coming from the instrument panel choke light, when
disconnected from the oil pressure switch, will measure voltage because it is the "ground side" of the "choke light." With the ignition ON, engine not running, the instrument panel choke light "grounds" through the choke heater via Ckt 931, illuminating the choke light. However, there isn’t sufficient current flow through the choke light to "heat" the choke heater.
As a test of the above and to aid understanding, disconnect Ckt 931 from the oil pressure switch and touch it to ground with the ignition ON and the choke light will illuminate.
However, when the engine starts and power is supplied to the choke heater through the oil pressure switch, via Ckt 350, the choke heater will "heat." At the same time, 12 volts is supplied to "both sides" of the choke light and current flow through the choke lights ceases, so the choke light goes out.
The choke light serves as an indicator to warn the driver if the choke heater fails by burning out, or is disconnected, or if 12 volts isn’t supplied to the choke through the oil pressure switch after start up.
The "ignition fuse" supplies key-switched power to various accessories - NOT to the engine's ignition system. To help with other issues, tell us a little more about the symptoms and what you have already done.
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