Hey guys, new here. starting to work again on my 73 so maybe i can get her back on the road next year. ran into a few issues, and found your site from googling info on it, so i figured id register.
first the story, fuel pump wasnt working, replaced it, still nothing, turned out to be a new DOA pump, car would start, for a second, with fuel in the carb. once i got that situated, the carb started pumping fuel out the top. pulled to float bowl, cleaned it out, and it seems to be ok.
now the problem. sometime during the numerous time i cranked the car over and over working on the pump, the interior lights(courtesy) stopped working. at around the same time, im guessing, the car stopped trying to start. it will crank and seems to want to start, but never gets there. can these 2 things be related?
wanted to add, all exterior lights work(as well as they did before!) i have a wiring diagram but it is a little blurry and hard to read, and i havent found where these would be related from the diagram. also, i didnt see any blown fuses, unless there is another fuse box than the one under the drivers side dash.
didnt pull the pulg yes yet, but i put a multimeter on the coil. key on, engine off(obviously), get 12ish volts on the positive side, nothing on the negative. from what i am to believe, i should have power on both sides at this point.
this all started from over cranking trying to get the fuel pump running. so some how, these 2 electrical issues are tied together, or at least a major coincidence. ive been scanning a wiring diagram(i have a couple that are slightly different) and dont see much that could tie these together.
i am also posting in corvette forums, as i have been a member there for a while. since i got my car back after my dad passed away. here is my latest post there.
" so, upon further inspection, the wire from the - side of the coil, was spliced into a wire coming from under the dash, that went to the distributor. that is not at all what the wiring diagram shows. for a moment, i was showing 26v at the + side of the coil, but couldnt replicate it. still nothing on the negative side. this is a newish coil btw. and like i said, it did run before on it. i removed the splice and ran straight from the coil to the distributor. no change.
The key warning buzzer still works, still no courtesy lights, and nothing on the - side of the coil. i did notice the acc pin(just above the ign pin with the pink/white wire)on the fuse box had a brown wire coming out, with a connection in it, and there was some melting on the black connector part(not against the fuse box, but about 3 inches down the wire) and it looks like a wire once was soldered onto it, but i cant find that.
my wiring is a mess, but it did work before....there must be something melted or grounded out. i could probably rewire the car int the time it is taking me to search all this out...
so back to the original issue, no courtesy lights, no power to - side of coil. can they be connected? or coincidence? i'll take the car starting over the courtesy lights at this point, but i have a feeling these are connected."
so i tested the coil. 12v at the + side, nothing at the -. i was able to get 26v at th + side again, then when cranked it went back to 12. when cranking, i got about 7v on the - side. i tested the resistance on the coil, and got 2.1 on the main coil, and 8 on the secondary( + side and center). that seems low to me.
i pulled the distributor cap, and bumped it until the points were open so i can test later but im headed in the electrical direction at the moment. i think my coil is bad due to the low readings i got, but once i figure out the electrical, i think the ignition will also be fixed.
i pulled the courtesy light bulb holder out and tested it, im getting 26/27v on the white wire. i'm also getting 27v on the pink/black wire thats supposed to go to the coil per the diagram. it must be spliced into a black wire at some point, because it is black at the coil. anyhow. why am i getting 26v? this should be 12 should it not?
not getting into semantics, i rechecked the wires.
6v at the + side of the coil. nothing at the negative. 12v on the white wire for the courtesy lights, no continuity to ground. orange wire on the left courtesy light. 12v across the battery. so i have no ground i guess...where in the world do i start looking for that? its only the engine starting and the courtesy and dash , as they are connected, lights that arent working.
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
When you checked the coil, you need to measure between the secondary and - terminal, not the + terminal. The two windings are connected on the ground side. The secondary winding should be considerably higher than the primary. The coil is basically a transformer.
Not sure where the 26V reading is coming from assuming your meter is accurate. Since you got 12V-13V at battery, meter must be OK. Just be sure your meter is on a DC setting.
i may have ben on the negative side, i cant remember, but i'll check it again just to be sure. the 26v i occasionally got was because on occasion i turned the multimeter switch to AC because im an idiot sometimes! going to grab a new coil and try to figure out the courtesy light grounding issue tonight.
ok, so i have a new coil in, only getting 6v to the + side, nothing to the -. am i correct in thinking the distributor is what grounds the circuit? since there is supposed to be power on the - side of the coil, then passes through to the distributor. im wondering if the ground is bad there.
on the lights end, i grounded the white wire as a test, and do get courtesy lights, but no gauge lights. the courtesy lights also do not go off over time. i let it sit for about 10 minutes with the key out and the doors closed.
so i finally pulled a plug, and i do have spark, so thats good. car used to start for a couple seconds when i put gas in the carb, but now it doesnt want to. going to either rebuild the carb or get a new one.
so on to the interior lights! still no idea...
the courtesy lights do work if you turn the headlight switch all the way to the left. i have some pics that i'll put up of something that i have no idea what it is, that doesnt look great too...
fairly certain the carb is gunked up. i had pulled the float bowl to check and clean it, when i put it back together, the bottom 2 big screws wont tighten down. im either going to try a rebuild kit, or just buy a new carb for it. its a Holley. has 7002-1 stamped on it, which through alot, and i mean alot, of searching, seems to be a 4165. im worried the 2 bottom screws are stripped.
but to answer your question, no, no fuel is getting through anymore(but fuel is finally getting up to it. it used to start up with putting fuel in the carb, for a second and run.
still trying to figure out what happened to the courtesy lights though.
well, for $40, the rebuild kit is coming in on Tuesday. i've never rebuilt a carb before, but its worth a shot. it had been pretty solid for 20 years! well, it worked even after sitting for 10 years. i think the rotten fuel line that i replaced and bad fuel pump finally gunked it up. already have the carb off and half apart. looks pretty easy.
as for the courtesy lights, i'm still tracing wires. my wire loom is not what you would call...good....
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