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I walked past my 1977 F150 with a 351M today and noticed a buzzing noise. I popped the hood and it seems to be coming from the ignition control
module. The ignition was off, I last drove it (just moved it in the driveway) yesterday. Battery is dead today, no start, no click, no headlights, just
buzzing. Do you think the problem is the ignition module or the ignition switch? Thanks for any help!
My OEM module was still on my '77 that day in '15 or '16 when I opened the hood at work, and old time parts man standing there was surprised to see it, said they were famous for dying. I had never heard that, but mine had leaked some potting onto the apron so I replaced it, the replacement was new in the box, but had been in my truck as a back up for probably 20 years and I had to cut the box to get past it's leaked potting and it had never been used. Replacement died a week or so later, but after cool down, got me home. Now the OEM one is my spare.
Tbear, I appreciate the response and the story. I am thinking ignition assembly as well, because the ignition module should not have power when the ignition is off and the keys are not in the truck.
Tbear, I appreciate the response and the story. I am thinking ignition assembly as well, because the ignition module should not have power when the ignition is off and the keys are not in the truck.
Was my thought too ... my '77 has nothing that isn't shut off when the key comes out. For the DS module under the hood to see any juice, the ignition switch has to pass it along somehow.
AFAIK there are no moving parts in a Duraspark module. Nothing inside it to buzz, just electronics. Duraspark module just shuts down after a while of not receiving an input from Distibutor or the start wire if key is left on. A mechanical voltage regulator, I've heard buzz after key left on and battery going dead, but that's on the other side of engine bay. Not saying it didn't happen but interesting. I've been lucky I guess, only had 1 fail in 46 years of driving with them, when it did go out it gave me 3 warnings first.
When I was a little kid, my Mom had a Maverick which started having problems like draining the battery, and the radio coming on when the car was off and the keys were in the house. I think the dealer threw parts at it as the car went back two or three times, but if I remember correctly, it was the voltage regulator.
Regulator, solenoid will buzz. If it’s the ignition box, with electronics strange things can happen . Replace it, it it persists check for voltage on incoming wires. If that is the problem replace the ignition switch.
Duraspark gets no power what isn't enabled by the ignition switch first. If the ignition switch is off, if the ignition switch is sound, the Duraspark gets no power. If the Duraspark buzzes while the ignition switch is off, then it's getting power and it's because of a bad ignition switch or other wire fault in the harness.
And if the Duraspark box is getting hot when the keys/ignition is off, then it is getting power. Don't bother asking how I know, because I once retrofitted the Duraspark system from another car onto a 1968 Cougar 289/302. Later that night, I was going over the wiring diagrams for both cars, and I realized I'd made an error which left the box powered. I immediately went out there to correct it, and sure enough that box was hot to the touch. But it all still worked after I got the wiring right.
