No Power in the car, but there is in the engine bay

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evans68cuda

evans68cuda

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Just got a brand new battery and after having spliced my aftermarket gauges into my headlight switch, I went to test them out and there was no power at all. No crank, no lights, nothing. The battery reads 12.6v but when I go to turn the key, nothing happens. Ive been reading lots of forums on here and tried everything they said, but still can't figure it out. I can turn the motor over but jumping the starter relay, the alternator reads 12v when the key is in the on position, I then checked the fused link and that is also good. I have power on the engine bay side of the bulkhead for the ignition switch, and when I turn the key on, my voltmeter turns to 12.5 volts(I have it connected to something in the engine bay, I think the voltage regulator) But there is no power at the fusebox, but I do not see any reasons as to why. Any ideas????
 
Probably the connection at the bulkhead.
Some bypass the old power and run a thicker wire from the battery straight to the fuse box.

But it's just a process of elimination.
There's got to be a break some where between the battery and fuse box.
 
figured it out and I feel like an idiot, apparently the steering column needs to be grounded. I had it out becuase I just insatlled the headers and hadnt put it in yet. Oh well, live and learn. But i bypassed the ammeter while I was there. Just took the wires off the back off the dash and connected them. Ill go in and wrap it with electrical tape tomorrow.
 
Its not enough to just connect the ammeter leads together removing the gage from the system. Its still wired to where ALL the alternators output amps go into the bulkhead, then back out and on to the battery. You need to bypass the bulkhead and have the alternators output go straight to the battery.

I disagree with one part of schematic #2 showing to bypass the bulkhead connector altogether, unless your bulkhead connector is melted. However if the bulkhead connector is not melted when you do the bypass, you can keep your feed wires coming from the battery thru the bulkhead connector as the amperage is now low enough and split between 2 wires to where the connector should not melt now. See schematics below Do this too.

amp-ga18.jpg


amp-ga27.jpg
 
Maybe I should just hook it back up. I have pretty basic wiring. No AC, no electric fuel pump, no cooling fans, just an MSD box and I have some speakers I was thinking about putting in but nothing crazy.
 
Something aint right in what you've posted. The steering column doesn't have to be grounded to get power to the fuse box, headlights, etc... The column ground jumper does nothing more than ensure a ground path for horn and shift indicator lamp.
A column shift will loose the neutral safety set when the column is lowered preventing start. The inst' panel lamps don't work when that panel isn't chassis grounded.
In my opinion, If there is no evidence of overheating at fusible link or bulkhead connections, there's no reason to bypass or reroute anything. If it ever does fail, it likely will fail there where its supposed to (outside the cabin ). Even then you wouldn't have to go "mad" or "mader" in repair. New bulkhead terminals are available. Previously unused ports in the bulkhead are available.
I don't believe any of this is relative to your "no start" anyway. Good luck with it.
 
I only posted the bypass to help prevent a possible future problem. I have all new M&H wiring in my car from front to back. However I still did the bypass, and ran an 8 gage marine grade alternator wire, but i also have a 50A alternator.
 
Actually I didn't intend for the OP to jump into a bypass project. What was in my head is the simplified diagram that shows how the main power is distributed. If you have "no power" it is almost always related to battery connections/ cables, the fuse link, bulkhead connector, or ammeter connections. "In rare cases" ------hey it's happened-------the "welded splice"

This is the simplified diagram of the FACTORY wiring

amp-ga18-jpg.jpg


Follow along the "functional path" NOT "electron flow." From the battery, depending on year, the power "arrives" at the big stud on the STARTER RELAY.........From there through the FUSE LINK........through the BULKHEAD (RED) and to the AMMETER.........through the ammeter and out on the BLACK ammeter wire and to the WELDED SPLICE. (This splice is a few inches from the ammeter up under the dash)...............

From there things branch off various years / models......

to HEADLIGHT SWITCH
to FUSE PANEL HOT BUSS
to IGNITION SWITCH
 
67Dart273 said:
Actually I didn't intend for the OP to jump into a bypass project. What was in my head is the simplified diagram that shows how the main power is distributed. If you have "no power" it is almost always related to battery connections/ cables, the fuse link, bulkhead connector, or ammeter connections. "In rare cases" ------hey it's happened-------the "welded splice"

This is the simplified diagram of the FACTORY wiring

View attachment 1715096411

Follow along the "functional path" NOT "electron flow." From the battery, depending on year, the power "arrives" at the big stud on the STARTER RELAY.........From there through the FUSE LINK........through the BULKHEAD (RED) and to the AMMETER.........through the ammeter and out on the BLACK ammeter wire and to the WELDED SPLICE. (This splice is a few inches from the ammeter up under the dash)...............

From there things branch off various years / models......

to HEADLIGHT SWITCH
to FUSE PANEL HOT BUSS
to IGNITION SWITCH
Click to expand...

If none of this is working, start at the fuse link, follow it to the terminal in the bulkhead connector. Use a meter or test light, you have power there at the bulkhead connector?

Yes? Then reach up under the dash and feel and find the ammeter wires, and with "something on" (like the dome or headlights) wiggle the ammeter connections, are they loose? Spark? Power comes and goes?

If not, then pull your bulkhead connector apart, inspect, repair, etc

DO NOT GET LED down the wrong path!!! With all power "off" and IF YOU DO have power at the bulkhead connector, this may be an erroneous "reading" due to a POOR/ INTERMITTENT connection. Turn on the headlights and see if that "goes away."
 
I was planning on doing the 60 amp alternator upgrade because if the speakers and msd, so that's why I was thinking about the ammeter bypass. But yes I checked every connection several times and they were all tight. I took off the bulkhead connectors, used a wire brush on the terminals to clean off any corrosion or debris, and used compressed air to clean it all out. I left the doors open and with the battery connected, I touched the steering column to the floor and all the lights turned on.
 
Even with removal of the ammeter in the circuit "ALL" your alternators output still goes through the bulkhead at the firewall. With a 60A alternator you should seriously upsize its output wire to an 8ga wire, and bypass the bulkhead altogether like the schematic shows but run it straight to the battery, add in a 12ga fusible link between the 8ga alt wire and the battery. If you do not so this you run an even higher risk of melting that bulkhead. The stock alt output wire is i believe only 12ga. Thats good for 20A output, barely ok for up to 30A if you decide to do the bypass, and i do recommend it before you fry your bulkhead connector especially with running a 60A alternators output thru the bulkhead, Do not buy wire thats listed as CCA wire. Its junk. Its copper clad aluminum. Cheap chinese chit. Buy marine grade AWG 8ga. You can buy from pico wiring 12ga fuse link material. I made up multiples of this 12ga fuse link to keep 1 or 2 in my glovebox.

If you want, i can post pix of my setup w the fuselink at the battery. My wiring is currently being mocked up. My "battery" is a cardboard box that fits the battery tray lol. Once its done, it will be removed so i can finish up my engine compartment and paint it.

If you decide to run that 60A and you dont bypass the bulkhead and run it straight to the battery, and then you "smoke" the bulkhead connector, well then you will have a bigger problem and a non working car once you "let the magic smoke out"
 
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