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longbridgehealey
Obi Wan
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If I was considering putting in line fuses into my 100-6 wiring, what all should I fuse?
thanks!
thanks!
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In line fuses
- Thread starter longbridgehealey
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I have the following fused:
You might also consider the tail lights and license plate light.
- overdrive circuit
- fuel pump
- the five circuits that come from the 35-amp fuse are individually fused (the 35-amp fuse is now used for the fuel pump fuse).
You might also consider the tail lights and license plate light.
OP
longbridgehealey
Obi Wan
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Yep, got driving lights. Thanks, Keoke
RAC68
Darth Vader
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Hi All,
While you are installing in-line fuses, I suggest you make a list containing the circuit/component covered, the fuse amperage and, most important, the location of the fuse. Also, I strongly recommend that you also carry an updated copy of your fuse directory in the glove box along with 1 or 2 spare fuses of each amperage installed.
The beauty of in-line fuses is that they are installed into the covered circuit and, therefore, can be located anywhere. I have used in-line fuses extensively in my BJ8 to cover every critical circuit and key component...including my sound system. Although I have not had an issue causing a fuse to blow, I have pulled a fuse to deactivate/separate a circuit when addressing a circuit or component modification. This can also be helpful when experiencing a component anomaly/issue when on the road and needing to continue home.
One last thought. If I remember correctly, power for your headlights comes from your ignition switch and passes through your light switch and dip (high/low beam) switch before arriving at your headlights and (depending on how you have wired them) driving lights. Depending on the type of headlights installed, a substantial amount of amperage will be passed over very light wiring. If you haven't already done so, consider installing (3) relays to bring fused power to your headlights/driving-lights directly from your alternator/generator/voltage-regulator. This would allow a significant reduction in power passing through your original thin-wired circuits and components to that needed for switching the relays with an improved probability of extending circuit and component longevity and reliability.
Enjoy your Healey,
Ray(64BJ8P1)
While you are installing in-line fuses, I suggest you make a list containing the circuit/component covered, the fuse amperage and, most important, the location of the fuse. Also, I strongly recommend that you also carry an updated copy of your fuse directory in the glove box along with 1 or 2 spare fuses of each amperage installed.
The beauty of in-line fuses is that they are installed into the covered circuit and, therefore, can be located anywhere. I have used in-line fuses extensively in my BJ8 to cover every critical circuit and key component...including my sound system. Although I have not had an issue causing a fuse to blow, I have pulled a fuse to deactivate/separate a circuit when addressing a circuit or component modification. This can also be helpful when experiencing a component anomaly/issue when on the road and needing to continue home.
One last thought. If I remember correctly, power for your headlights comes from your ignition switch and passes through your light switch and dip (high/low beam) switch before arriving at your headlights and (depending on how you have wired them) driving lights. Depending on the type of headlights installed, a substantial amount of amperage will be passed over very light wiring. If you haven't already done so, consider installing (3) relays to bring fused power to your headlights/driving-lights directly from your alternator/generator/voltage-regulator. This would allow a significant reduction in power passing through your original thin-wired circuits and components to that needed for switching the relays with an improved probability of extending circuit and component longevity and reliability.
Enjoy your Healey,
Ray(64BJ8P1)
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Good points Ray.
When I installed the relays for my head and driving lights, I installed an auto reset circuit breaker to protect against shorts, but allow it to reset when the fault is gone. Wouldn't want to blow fuses in the dark.
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Believe it or not, that license plate light fuse is critical. Lots of wiring loom fires get started from those wires being chafed.
OP
longbridgehealey
Obi Wan
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Wow, this is a lot of great information, guys. Thanks a lot! More questions coming, I’m sure. Where best to place fuses, what size to use, etc. we’ve had this Healey on the road for over forty years, weathered two wiring fires, it’s time to give it some helpful upgrades!
RAC68
Darth Vader
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Hi John, Rick,
John,
Very good point. I was thinking of changing to a circuit braker but was wondering if it would be functional. If a short occured in the headlight power feed circuit (apposed to the switching circuit), I can see an automatic reset would be beneficial. Have you also install a circuit breaker on the relay's switching feed circuit as well?
Rick,
I fully agree. I was a recipient of a short in the rear license plate light that resulted from water penetration into the light housing when washing the car. The short caused the insulation of a few of the adjacent wires in the rear harness to melt and needed to be replaced with wire outside of the harness. After my experience, I discovered that BJ8 Phase 2s had a fuse originally installed but never heard anything about its presence or reason for its installation.
Ray(64BJ8P1)
John,
Very good point. I was thinking of changing to a circuit braker but was wondering if it would be functional. If a short occured in the headlight power feed circuit (apposed to the switching circuit), I can see an automatic reset would be beneficial. Have you also install a circuit breaker on the relay's switching feed circuit as well?
Rick,
I fully agree. I was a recipient of a short in the rear license plate light that resulted from water penetration into the light housing when washing the car. The short caused the insulation of a few of the adjacent wires in the rear harness to melt and needed to be replaced with wire outside of the harness. After my experience, I discovered that BJ8 Phase 2s had a fuse originally installed but never heard anything about its presence or reason for its installation.
Ray(64BJ8P1)
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I'd recommend that you fuse as many circuits as you can and do so separately so the value of the fuse is not much more than about twice the anticipated maximum current draw, calculated by dividing the number of watts by the voltage. So the fuse for a lighting circuit for a 50 watt bulb in a 12 volt car should be around 10 amps. Bunching appliances together and powering them though one big fuse offers little more protection than a 16d nail and puts all the wiring at risk.
Though fuses are used to protect an appliance in case it develops some internal over-current situation they also protect the wiring leading to it which can be destroyed whether the fault is within the appliance or the wiring itself, such as when insulation is compromised allowing a current-carrying wire to contact a ground.
Locating a fuse as close as possible to the power source offers more protection to the circuit, or--put differently--that portion of wiring between the hot source and the fuse is unprotected from damage due to overloading and the wire itself becomes a fuse.
Lots to consider....
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There is a great article buy Steve Maas containing more than you may choose to know about fuses on John Sims' site at: http://www.healey6.com/Technical/Electrical Mods.pdf
It is Sprite-specific but as with so much LBC stuff the knowledge is directly transferable to Big Healeys as well.
It is Sprite-specific but as with so much LBC stuff the knowledge is directly transferable to Big Healeys as well.
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I purchased one of his fuse blocks for my BJ8. It has six fuses. The difference between early and late big Healeys is the green wires are on the opposite side.
Attachments
Rob Glasgow
Jedi Knight
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Not only does Charlie make a good product, he is a great guy.
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He also includes a wiring diagram with what size fuse goes with what circuit.
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Ray,
The control circuit is from a different source, and it has a fuse. The headlights, driving lights (and AC) are fed from a bus bar that comes directly off the alternator and starter solenoid.
Keoke
Great Pumpkin
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considering-Michael-Oritt Last post:
Where he mentions that the wire protects the FUSE You can Perform what is called a marriage , identical fuses are placed one at the power source and the other at the load. This adds a bit of complication but will generally solve the problem.
Where he mentions that the wire protects the FUSE You can Perform what is called a marriage , identical fuses are placed one at the power source and the other at the load. This adds a bit of complication but will generally solve the problem.
Michael-Oritt
ocating a fuse as close as possible to the power source offers more protection to the circuit, or--put differently--that portion of wiring between the hot source and
the fuse is unprotected from damage due to overloading and the wire itself becomes a fuse.????
ocating a fuse as close as possible to the power source offers more protection to the circuit, or--put differently--that portion of wiring between the hot source and
the fuse is unprotected from damage due to overloading and the wire itself becomes a fuse.????
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RAC68
Darth Vader
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Hi All,
Michael,
Michael,
Thank you for the reference to Steve Maas's document. From my short scan of the article, it seems like a worthwhile read.
Keoke,
A very good point.
When viewing the gauge of wire used within the original harnesses, it is not hard to understand that they will not support today's common electrical component expansions. Additionally, the fact that original wiring (and insulation) hardens with age and furthers the risk of their ability to maintaining the complement of components originally designed to support. These factors justify why many of use have taken the approach of creating separate new wiring harnesses for all new electrical additions (fans, lights, sound system, etc.) and are trying to reduce to control functions any operational amperage draw through my original harnesses.
Thanks again,
Ray(64BJ8P1)