I’m finally starting to actually tie in (solder) all my connections under the dash, but I’ve hit a snag…
The vehicle is on ’03 F150 Supercrew and I’ve pulled wiring diagrams off the Internet from about 5 different sources. Each source references the exact same wires for the Ignition1 and Ignition2. Each document I read states that the proper way to test these wires is to check voltage in the different key states; the ignition wires should show 0 volts on all but RUN and START (crank), at which time they should both be at 12 volts. It also states that there should be no more than just a several tenths of a volt drop when you go from RUN to START.
My problem is that both ignition wires show a significant drop (down to 3-6 volts) whenever I go from RUN to START. I’ve checked every single wire and not one of them maintains a 12 volt load while cranking (although I don’t believe I tested the 3 12 volt constants).
So my questions are: A) What’s the likely hood of my wiring being different than how it’s supposed to be, and B) What’s the deal with the voltage drops?
Is it possible that the voltage drops are due to a less than fully charged battery? The car hasn’t been driven really at all since I’ve started working on it (about a month and a half considering all of my little projects).
Any thoughts?
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Bill
(SO MUCH FOR ABOVE, HERE'S THE POST FORMATTED PROPERLY)
I’m finally starting to actually tie in (solder) all my connections under the dash, but I’ve hit a snag…
The vehicle is on ’03 F150 Supercrew and I’ve pulled wiring diagrams off the Internet from about 5 different sources. Each source references the exact same wires for the Ignition1 and Ignition2. Each document I read states that the proper way to test these wires is to check voltage in the different key states; the ignition wires should show 0 volts on all but RUN and START (crank), at which time they should both be at 12 volts. It also states that there should be no more than just a several tenths of a volt drop when you go from RUN to START.
My problem is that both ignition wires show a significant drop (down to 3-6 volts) whenever I go from RUN to START. I’ve checked every single wire and not one of them maintains a 12 volt load while cranking (although I don’t believe I tested the 3 12 volt constants).
So my questions are: A) What’s the likely hood of my wiring being different than how it’s supposed to be, and B) What’s the deal with the voltage drops?
Is it possible that the voltage drops are due to a less than fully charged battery? The car hasn’t been driven really at all since I’ve started working on it (about a month and a half considering all of my little projects).
Any thoughts?
-------------
Bill
think about it, you are using the battery to crank the starter motor. there is going to be more than several tenths of a volt in drainage. its bad if you get like 9 volts (weak battery), but thats going to suck some juice! so besides the voltage drop not matching, you are finding the correct wires. the starter wire will sometimes only show 10v when you crank the key.
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MECP certified installer