Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 10-15-2018, 11:42 AM   #1
rfitzpatrick
Member
 
Join Date: May 2018
Location: Coral Springs, Florida
Posts: 64
Default Fues-Block For My Head-Lamps

OK, I've a heated discussion between myself and my Model A CrewChief (H Jones) -- there's yellow wire coming out of my head-lamp switch going to my alternator as it's source of power -- am I right? If I were to install a seperate fuse-block, would this allow me the same protection as leaving it routed to the starter fuse-block? Would this cause any power disruptions to any other electrical system, limited as they already are? What I'm wanting to accomplish is having my entire lighting system on a seperate fuse-block so that if a head-lamp shorts, it will not shut me down -- the main thing at risk here is Mr. Jones pride.


Thanks
rfitzpatrick is offline   Reply With Quote
Old 10-15-2018, 12:42 PM   #2
Jim/TX/GA
Senior Member
 
Jim/TX/GA's Avatar
 
Join Date: May 2010
Location: Houston, TX & Hiawassee, GA
Posts: 1,205
Default Re: Fues-Block For My Head-Lamps

That is an excellent idea and you have chosen the correct place to put the fuse.

Then, if you have a short in the lighting system, it will not kill your ignition, just your lights. You can limp home without lights and figure it out.

I know one person that has sent power back to his brake light switch with a new, dedicated wire that does not feed off of that yellow wire going into the headlight switch. It is fused and feeds off the post in the terminal block on the firewall that holds the yellow/black wires. This is so that if the fuse that you add to the headlights blows, he still has brake lights when driving. Not a bad idea, but more of a deviation from original, which makes troubleshooting more difficult in the future.
__________________
Jim Cannon
MAFCA 2018 Technical Director
Your Model A Technical Questions answered by email: tech@mafca.com
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/TX/GA is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 10-15-2018, 01:51 PM   #3
Badpuppy
Senior Member
 
Join Date: Dec 2017
Location: Guthrie, OK
Posts: 221
Default Re: Fues-Block For My Head-Lamps

With standard wiring there are two yellow wires from the gen/alt heading downward. One goes to the lighting switch, the other to the horn. You can add an inline 20A fuse/breaker at the alternator to serve them both. But as Jim implies, if it opens you lose all the lights.

Original purpose of the battery fuse was to protect it from discharge caused by a stuck cutout contact. It never provided protection to anything else. Doesn't hurt to leave it in.

Last edited by Badpuppy; 10-17-2018 at 04:38 PM.
Badpuppy is offline   Reply With Quote
Old 10-15-2018, 01:51 PM   #4
rfitzpatrick
Member
 
Join Date: May 2018
Location: Coral Springs, Florida
Posts: 64
Default Re: Fues-Block For My Head-Lamps

Jim
While I can see this deviation from original -- it would also allow me to trouble-shoot the electrical systems indenpendently -- as when I have an electrical problem, I quit driving until it's located and repaired. If it's the head-lamps, I would still drive, just not at nite.
Thanks
rfitzpatrick is offline   Reply With Quote
Old 10-15-2018, 03:14 PM   #5
Jim/TX/GA
Senior Member
 
Jim/TX/GA's Avatar
 
Join Date: May 2010
Location: Houston, TX & Hiawassee, GA
Posts: 1,205
Default Re: Fues-Block For My Head-Lamps

The deviation I was warning about had to do with adding a new power feed to the brake light switch. That's a deviation.

The addition of a fuse where you are talking about is very clean and obvious. Not a deviation, to me. Just common sense.

And I would fuse the horn power feed wire separate from the feed to the light switch. With that horn wire hot all the time and having the ends just clipped into the horn motor, it is very possible for the wire to get shorted out inside the horn when messing with it or when driving down a bumpy road. You want that fuse to blow before your wiring starts to burn.

So you are really talking about adding 2 fuses there. I fully support that. Use weatherproof fuse holders and you are good to go. Yes, it also helps with troubleshooting.

Remember, if you drive during the day with the fuse to the light switch out, you have no brake lights.

.
__________________
Jim Cannon
MAFCA 2018 Technical Director
Your Model A Technical Questions answered by email: tech@mafca.com
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/TX/GA is offline   Reply With Quote
Old 10-15-2018, 07:17 PM   #6
Ruth
Senior Member
 
Join Date: May 2016
Location: Glide, Oregon
Posts: 123
Default Re: Fues-Block For My Head-Lamps

I added a 20amp circuit breaker to the yellow wires coming from the alternator to the light switch. It is hidden in the frame rail next to the alternator.




Last edited by Ruth; 10-15-2018 at 07:25 PM. Reason: I hate auto-spell check...
Ruth is offline   Reply With Quote
Old 10-15-2018, 07:25 PM   #7
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 5,749
Default Re: Fues-Block For My Head-Lamps

Quote:
Originally Posted by Ruth View Post
I added a 20amp circuit breaker to the yellow wires coming from the alternator to the light switch. It is hidden in the frame rail next to the alternator.


Looks like your light switch is upside down.


Bob
Bob C is offline   Reply With Quote
Old 10-15-2018, 07:56 PM   #8
Ruth
Senior Member
 
Join Date: May 2016
Location: Glide, Oregon
Posts: 123
Default Re: Fues-Block For My Head-Lamps

Quote:
Originally Posted by Bob C View Post
Looks like your light switch is upside down.


Bob
Haha, Good eye Bob. I had a Brain Phart while putting the switch on from under the car. That is a old picture and it has since been "repaired". I have also added a PowerGen since then.

Ruth is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 07:27 PM.