Originally Posted by oldude48
I have an '86 Bonneville with the 305 V8 and it'* got about 196,000 miles on it. Just lately the choke light comes on intermittently. When it does this, the oil pressure and ammeter gauge needles move to the left and then move back to normal position as the choke light goes out. I have no idea what this means? Any ideas?
It'* probably your alternator, or more specificly, the charge indicator wiring on the alternator (pin 1 on the 2-pin connector on the alternator case)
The choke relay is being fed not to ground, but to the charging pin on the alternator. It sounds like a goofy arangement, but that'* the way GM did it to run the choke heater on Rochester carbs....in other words, when the alternator is working, the choke is automatically turned off. It uses the changes in resistance to act as a cutoff switch to the choke. (Unlike a Holley or anybody elses electric choke that is run off a hot in run circuit without any relay involved.)
The trick to figuring this out is ignoring the choke lamp, and focusing on the sudden dip in the electric oil pressure gauge and voltmeter...both indicating a voltage drop in the electrical system that coincides with the choke light comming on.