ADDITIONAL FUSING FOR EXTRA PRECAUTION?

[robert_ellison]

I was reading that it is advisable to add a 5 amp in line fuse to the red wire leading to the boot lights. Are there any other precautionary fuses that might be added to limit any potential electrical damage?
I am preparing to start my car finally and, as I have discovered that my wiring set up seems to be a combination of layouts I'm not sure everything is hooked up right all around. Limiting the damage just in case would make me feel better, even if it might be over-kill.

Thanks

 

[GregW]

Personally, I dislike inline fuses. I prefer the fuses to be all in one location. A lot less investigating when trying to find one that is blown. That said, if you're only going to add one to the red wire, well, I guess an inliner would be best.:m If you have doubts about the wiring, I'd take the time with an ohm meter and check every circuit in the car before running juice through it.

 

[bighealeysource]

Hey Robert,
You probably have been reading my woeful tale of the burned up wiring harness
so definitely follow Keoke and others advice and put in that fuse. I am not
looking forward to putting in the new wiring harness but received some great
advice and maybe it won't be as bad as I thought. But you can be sure I will
have that inline fuse installed.
Good luck,
Mike

 

[andrea]

I was reading that it is advisable to add a 5 amp in line fuse to the red wire leading to the boot lights. Are there any other precautionary fuses that might be added to limit any potential electrical damage?
I am preparing to start my car finally and, as I have discovered that my wiring ....

Hi Robert
One test with a limited- (10A) Battery charger with automatic protection -can limit damages at wiring harness
one in line fuse on the red wire near the S1 terminal of the LUCAS Light Switch is sure a good solution
Better can be more fuses in one fixed position under desk -and relay on Head light line -this can protect
Air blower motor
SU fuel pump
Tail Light
Head Lamp/fog Lamp
Aux Fan
I look at your future progress

 

[robert_ellison]

Thanks for the reply.

do you mean hook up charger to the pos & neg battery line without the battery in order to test? what will that show me (what to look for)

re more fuses is this relay on headlight line also protecting the other items:
Air blower motor
SU fuel pump
Tail Light
Head Lamp/fog Lamp
Aux Fan

or is it necessary to fuse each one?

By relay do you mean splice into the line to item and run to a fuse block? Would I do that for each item?

What size fuses would you recommend?

 

[Michael Oritt]

The topic of fuses always draws diverse opinions.

I am of the belief that each current-carrying circuit should as much as possible be fused separately and have two 6-position fuse panels on the firewall of my 100, one for circuits that are always hot (head and side lights, driving lights, horn, radio memory, auxiliary fan and one spare) and the other for circuits switched by ignition (radio, fuel pump, heater fan, wipers, and two spares).

For lighting circuits you can approximate the amperage by dividing the total number of bulb watts by 12. For unknown loads such as horns or wipers you can start with small fuses and upgrade them as they blow or not.

 

[andrea]

Thanks for the reply.

do you mean hook up charger to the pos & neg battery line without the battery in order to test? what will that show me (what to look for)

re more fuses is this relay on headlight line also protecting the other items:
Air blower motor
SU fuel pump
Tail Light
Head Lamp/fog Lamp
Aux Fan

or is it necessary to fuse each one?

By relay do you mean splice into the line to item and run to a fuse block? Would I do that for each item?

What size fuses would you recommend?

Yes you must connect only the charger to the car-
this are a good working solution for new harness
you can probe one single section of circuit when
it is finished- section can be-- Starter and Ignition -Tail light/H Light- brake L.-Heather mot.- Whipper-

Relay is needed only to protect the LUCAS light.switch. from hing wattage absorbed by halogen lamps on H.L. and Fog

Yes one fuse must protect only a single line
this help to easy find a short

This are my idea for my project car I think wiring my car next winter
I tray to improve my Engl. please escuse me for mistakes
Andrea

 

[richberman]

I was reading your post from last year regarding fusing as I'm just undertaking a total restoration of a 57 100/6. As I have become used to having my headlights automatically turn off when the ignition is off (spoiled by many years of Toyotas, Volvos and Saabs), I was wondering how to wire my headlights such that they will shut off when the key is removed. Any thoughts?
thanks in advance.
rich

 

[Randy Forbes]

Put the headlight power (solid blue wire) through a relay; energize the relay with the ignition circuit.

Well, that'd work for the headlights, but now the sidelights would still be on!

Use a double-pole relay, and put the solid red through the other set of contacts.

Now, if you want to illuminate the car, you have to switch on the key, also not so desireable!

How about a relay that knows when the hdlts are on/ignition off? This could control a buzzer to remind you to turn off the lights.

Lots of possibilities...

 

[richberman]

Randy,
I'm thinking a relay to turn off headlights and sidelights. I won't mind turning the key to light it up. That's better than jumping the battery when I forget to turn the lights off.
So what kind of relay to buy?
thanks,
rich

 

[Randy Forbes]

12VDC single-pole.

Either a Form C set of contacts (common, normally open & normally closed; "normal" denotes status as if "on the shelf" or de-energized). Or, a normally open relay (contacts close when energized).

The blue w/brown can be lifted off the lighting switch and attached to the relay common contact. Then run from the normally open contact back to where you lifted the blue/brown wire from the hdlt sw.

One side of the relay coil attaches to chassis ground (use the same screw as mounts the relay) and the other side goes to the solid white ("hot" in run & start).

Wired thusly, you would have to leave your headlight switch in the full on position, and the lights would go on/off with the ignition switch.

If your battery voltage is iffy, it may not be happy trying to turn the starter, run the fuel pump and energize the ignition coil, all while the high beams are on. In that case, switch off the headlights for the starting sequence, or consider using a time-delay relay...

There are many possibilities to do this.

 

[richberman]

Randy,
Thanks for the thoughts...a time delay relay...I like it. So where does one purchase these relays?
rich

 

[Keoke]

I'm thinking a relay to turn off headlights and sidelights.

So what kind of relay to buy?

For the sake of simplicity Rich, purchase a Single pole single throw relay [ Bosch ] with a current rating of 10 Amp.---Fwiw-Keoke

 

[richberman]

Keoke,
Since I'm a newbee to this would you mind walking me through the specifics? Like what exact relay to buy and how to wire it into my 100/6 so my lights go out when the key is off.
thanks,
rich

 

[Johnny]

Keoke,
Since I'm a newbee to this would you mind walking me through the specifics? Like what exact relay to buy and how to wire it into my 100/6 so my lights go out when the key is off.
thanks,
rich

Rich, are you ever in luck. I just finished reading a great article with a step-by-step guide on how to do just what you're considering. The article is in Hemmings "Sports & Exotic Car" June 2010 issue. Probably still in the news stands. Under the column "DIY Weekend Project" page 66 titled "Brighter Headlamps Made Easy" how to add relays to get the most from your lighting systems, by David LaChance. I was planning on doing this project myself soon. Any AH owner could benefit from this article due to the diminished lighting of our cars. He tells you what to buy and how to install it with photos, great article.

 

[Keoke]

Keoke------------- :laugh: