Rewiring the 1948 F5
#1
Rewiring the 1948 F5
The ol’ ‘48 wiring has seen better days. Truck runs and drives around the yard powered by a 1968 Mustang 302, 12v generator system. Parked in a warehouse in 1970 and updated slowly over years. Mice ate most of the lighting wires up pretty good, so none of them work.
I bought a 12 circuit universal wiring harness to swap, a new alternator, headlight switch, voltage regulator, alt brackets, tail lights, bulbs all around, turn signal stalk, and starter. Took some pics (below) and plan is to remove the old and install the new. I’ve rewired a few old Mustangs, Broncos and a ‘66 F100, so hoping this one goes well. Always a little reluctant to mess with something that is working well. I haven’t looked under the cap, but points will be replaced with a Pertronix ignition module.
If you need any parts for your original harness, let me know. The truck runs and charges now.
I bought a 12 circuit universal wiring harness to swap, a new alternator, headlight switch, voltage regulator, alt brackets, tail lights, bulbs all around, turn signal stalk, and starter. Took some pics (below) and plan is to remove the old and install the new. I’ve rewired a few old Mustangs, Broncos and a ‘66 F100, so hoping this one goes well. Always a little reluctant to mess with something that is working well. I haven’t looked under the cap, but points will be replaced with a Pertronix ignition module.
If you need any parts for your original harness, let me know. The truck runs and charges now.
#4
So ran into the first challenge right out of the gate. The alternator mounts allowed the alt to interfere with the motor mount (maybe why the generator survived the previous owner’s motor swap). The new top bracket will work but the bottom (belt adjustment bracket) will have to be relocated to the inside fender, a mount tab fabricated, and the alternator will hang kinda the opposite of a traditional one.
In other words, I rotated the alternator all the up and will let it swing downward to provide belt tension. I will post a pic when I get it installed. Not getting to crazy with appearance of the brackets as a motor pull and refurbishment is on the horizon and things like spacers and brackets are a lot easier to address on a motor stand. Just making it work for now.
Although it would be cool to get the original gauges working, I foresee an aftermarket oil pressure and engine temperature gauge cluster. There’s already one next to the heater controls but it’s inop and ancient.
In other words, I rotated the alternator all the up and will let it swing downward to provide belt tension. I will post a pic when I get it installed. Not getting to crazy with appearance of the brackets as a motor pull and refurbishment is on the horizon and things like spacers and brackets are a lot easier to address on a motor stand. Just making it work for now.
Although it would be cool to get the original gauges working, I foresee an aftermarket oil pressure and engine temperature gauge cluster. There’s already one next to the heater controls but it’s inop and ancient.
#8
Hmm, good point. I will have to take a fresh look at it. My recollection is that to clear the motor mount, the alternator sits so that the adjustment tab is at the 9 o’clock position as you look from the grill toward the cab. The lower bracket would have to be significantly modified for length and the belt would have to be the exact length with no further adjustment ever possible.
The other option would be to figure out how to wire in the old generator to the new wiring harness that is set up for an alternator. I am not adverse to the genny, my first Mustang restoration was a 1964.5 V8 260 3 speed with the same unit. Worked great, I just thought this would be an easy swap/modernization.
Here’s the new harness wiring instructions for an alt, feel free to reply regarding wiring the genny with the new harness:
The other option would be to figure out how to wire in the old generator to the new wiring harness that is set up for an alternator. I am not adverse to the genny, my first Mustang restoration was a 1964.5 V8 260 3 speed with the same unit. Worked great, I just thought this would be an easy swap/modernization.
Here’s the new harness wiring instructions for an alt, feel free to reply regarding wiring the genny with the new harness:
#9
Hmm, good point. I will have to take a fresh look at it. My recollection is that to clear the motor mount, the alternator sits so that the adjustment tab is at the 9 o’clock position as you look from the grill toward the cab. The lower bracket would have to be significantly modified for length and the belt would have to be the exact length with no further adjustment ever possible.
The other option would be to figure out how to wire in the old generator to the new wiring harness that is set up for an alternator. I am not adverse to the genny, my first Mustang restoration was a 1964.5 V8 260 3 speed with the same unit. Worked great, I just thought this would be an easy swap/modernization.
Here’s the new harness wiring instructions for an alt, feel free to reply regarding wiring the genny with the new harness:
The other option would be to figure out how to wire in the old generator to the new wiring harness that is set up for an alternator. I am not adverse to the genny, my first Mustang restoration was a 1964.5 V8 260 3 speed with the same unit. Worked great, I just thought this would be an easy swap/modernization.
Here’s the new harness wiring instructions for an alt, feel free to reply regarding wiring the genny with the new harness:
edit:
Just follow the 64 1/2 generator diagram you posted and it should work.
The following users liked this post:
#11
Thread
Thread Starter
Forum
Replies
Last Post
Bob Ingram
1948 - 1956 F1, F100 & Larger F-Series Trucks
19
03-22-2021 01:00 PM
ffksummers
1961 - 1966 F-100 & Larger F-Series Trucks
4
10-10-2020 09:05 PM
2Scoops OfHooah
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
15
04-23-2020 06:05 PM
shanes66charger
1973 - 1979 F-100 & Larger F-Series Trucks
5
01-15-2017 05:58 PM