Buzzz

I decided to replace my engine wiring harness on my 72 and now I have no power to my fuse box. With a test light the engine harness has power to one wire on the block that plugs to the fuse box, it also has power to the main lug on the starter. I put a battery charger on my old harness on the red wire that goes to the horn relay and tested it and the same wires are live so I don't think there is a problem with the harness. I unbolted the fuse box and pulled it out a bit to check it and it looks fine. it seems like the power is not getting from the harness to the box. Other people on here have said there was no problems with this harness replacement which leads me to think it is something simple. Pretty much everything worked before I started.Is there any fuses that I should look for?

Buzzz

Now if I plug the engine harness back onto the fuse box the only thing that works is the horn.

jnb5101

check the male tabs on the fuse panel. sometimes when you assemble the two sides the contacts can become dislodged and not seat into the female side.

scottw

Agree w/ jnb. Unscrew the harness from the fuse box, make sure everything is straight on the connectors going to the fuse box and reconnect. Are you getting any power to the headlight harness that goes to the alt?

Buzzz

I disconected and checked the female terminals on the box, pushing a male test lead in. There is power on the top right blade on the engine harness so I put power to my test lead and checked all the terminals on the back of the fuse box. The top right wire in the light harness side of the box has power, so when plugged back together I checked that wire in the light harness and its live so I think the conection is good on the harnesses. There is power to the horn relay and the back of the alternator. Nothing at all will work but the horn, it works both by pushing the horn button or by grounding a terminal on the light harness plug. Over 25 years of restoring cars and I have never been stumped like this, I am considering having it towed to an electical shop but then I will have let it beat me.

jnb5101

the horn and alternator lead are fed directly from the starter lug thru a fuseable link, so the fuseable links are ok. did you check for voltage on the cabin side of the fuse panel? once the power comes thru the firewall, it's fed to the headlamp switch, the wiper door bypass switch and to the ignition switch. i don't think there are any fuseable links in those circuits. check for those voltages. if you have power on the engine side but not on the cabin side, there must be a problem in the fuse panel itself (i think?).

Buzzz

I checked the fusible links and they are fine. there is no power on the cabin side of the fuse box at all. Its strange because everything worked fine on it before. I am woundering if there could have been something cracked in the box and then broke when the engine harness was removed. If there is a problem in the fuse box would you have to change the entire dash wirring harness?

jnb5101

if you have power one one side of the panel and not the other, the problem has to be associated with the lug that connects to the red 12 gauge main wire. clean all the electric grease from the connections and make sure that the lugs can't be pressed out of position.

bobs77vet

it sure sounds to me like you had a failure inside the fuse panel. do you have an ohmmeter and can check continuity on the fuse panel ( battery disconnected)

collinde

Ive got the same problem. The fuse for the power in my fuse box was blown so I changed that. Put the key in, had a little buzz that faded and nothing. Fuse is ok still. Any idea's? All my lights work and horn, just nothing inside the car. Very frustrating issue.

derekderek

Go Back to Basics. You have power at the big lug on the starter. That's the big wire comes from the battery. Are you sure you didn't miss the smaller wire that goes from the battery terminal up to the fuse box? It could be unhooked and curled up tucked up above the starter or under the motor mount.

collinde

Man am I stupid!!!!!

Push the clutch in, car turns over!! No power to the radio, but that I can figure out. Still might be stuck changing the dash harness!!! Hope not