No power to the cab

[71iron-hayden]

I've got a 1971 F100 that is not getting power to the cab. I started it up last week and before being fully warmed up it just stalled out. Tried to re-start and nothing no: clicking, ignition, lights, wipers, heater motor, hazards, turn signals...nothing. I have spent the past week researching the topic and studying several wiring diagrams (thanks Fordification).

From what I have learned there appears to be a break somewhere between the starter solenoid (solenoid) and the main fuse box. I have jumped the hot side of the solenoid to the s terminal and the starter motor did fire up. That should confirm that there is a disconnect between the solenoid and the fuse box. Inspecting the solenoid (vs. what the wiring diagrams display) I only have one wire connected to the hot side of the solenoid, directly from the battery. The connection of the main line to the fuse and from the alternator appear to be connected through 1 or possibly separate boxes mounted to the passenger fender in between the battery and the solenoid. What would that/those units be? That/those should not be the voltage regulators as I thought the voltage regulator was mounted up near the front by the passenger side headlight/radiator/grill area.

I have located the large black (with yellow stripe) wire that is the main line to the fuse box within the cab and everything appears to be okay. Are there any connections that I should be looking for from the solenoid area to the fuse box? Are there any other suggestions, recommendations anyone can provide to help remedy this situation?

Thanks,

Iron Hayden

[DuckRyder]

This sounds like a kludge, a picture might be helpful.

I am pretty sure nothing that fits that description is on my truck.

[Jgriggs]

Fusible links OK?

[tsherry]

Once upon a time, three decades and change ago, I had something sort of similar happen on an old Falcon. Turned out that the ground on the back of the ignition switch had disconnected, killing just about everything. Took me some time to figure out....

[Thipdar]

I've got a 1971 F100 that is not getting power to the cab. I started it up last week and before being fully warmed up it just stalled out. Tried to re-start and nothing no: clicking, ignition, lights, wipers, heater motor, hazards, turn signals...nothing. I have spent the past week researching the topic and studying several wiring diagrams (thanks Fordification).

From what I have learned there appears to be a break somewhere between the starter solenoid (solenoid) and the main fuse box. I have jumped the hot side of the solenoid to the s terminal and the starter motor did fire up. That should confirm that there is a disconnect between the solenoid and the fuse box. Inspecting the solenoid (vs. what the wiring diagrams display) I only have one wire connected to the hot side of the solenoid, directly from the battery. The connection of the main line to the fuse and from the alternator appear to be connected through 1 or possibly separate boxes mounted to the passenger fender in between the battery and the solenoid. What would that/those units be? That/those should not be the voltage regulators as I thought the voltage regulator was mounted up near the front by the passenger side headlight/radiator/grill area.

I have located the large black (with yellow stripe) wire that is the main line to the fuse box within the cab and everything appears to be okay. Are there any connections that I should be looking for from the solenoid area to the fuse box? Are there any other suggestions, recommendations anyone can provide to help remedy this situation?

Thanks,

Iron Hayden

Your description sounds right to me.
In between the battery and the solenoid should be your horn relay. One pin from that goes to the hot side of your solenoid, another goes to the horn switch and the remaining wire should go to your horn(s).
Does your instrument cluster have idiot lights or gauges? This can impact which wiring diagram you are supposed to use. Then again, the diagram for '71 may include both.
Working from the wiring diagram for 1970, I see a lead from the hot side of the solenoid (Wire # 37, common to wire # 33) that goes to a 2-pin connector (which is located between the glove box and the RH door jamb, high up in the dash). The other wire for this connector is # 1, for the horn switch. Wire # 37 (which is Black with a Yellow stripe) goes to a connection with wires # 21 (Yellow, provides power to the Ignition Switch), 25 (Black with Orange stripe, provides power to the Headlight Switch) and 37A (Black with Yellow stripe, which feeds the fuse block.
Also on the hot side of the Solenoid, there is the Fuse Link which connects to wires # 38 and 152. Wire # 38 goes to the back of the alternator and wire # 152 goes to the Voltage Regulator (near the radiator)