23 replies to this topic

[Ethel]

Side/tail lights have always been fused.

 

You need to consider the potential load, not just the planned load. I'd be concerned if there's a permanent live, via a 15A fuse, within a cm of the exposed terminal of a wire running to earth. 

[Ethel]

 

Sorry, yes they did - but after the switch, so similar to fusing the main power feed on relays, not the switching circuit.

Yes that's correct the switch is technically unfused (due to these fuses being downstream of the switch)

 

If it was before the switch it'd have to handle the current drawn by the headlights too (without using relays), so all the wiring upstream of the switch, including from the sidelight terminal, would need to handle more current than needed to blow the fuse.

 

Using relays brings the current requirement down, but moving the fuse would still expose you to more ways to lose your headlights in blowing the fuse.

[Shooter63]

Funny enough I'm just doing a h4 conversion on my mk1 using relays to keep the load of my precious foot operated hi/low switch, I've gone totally OTT and used 4 relays one for each filament

Shooter

[MiniBGT]

I use just 2 dual out put relays, one for main beam and one for dip with all four outputs fused using fuse holder relay bases.  Yes, there is the possibility of a relay failure causing loss of both main or both dip beams, but the likely hood of both relays failing at once and loosing all beams is very low.

[Cooperman]

I had an electrical issue with my 1964 car a while ago. It was blowing one of the main 35 amp fuses. I managed to
isolate it to the wiper/fuel gauge circuit and stripped the speedo housing out. There was a bare connection on that circuit.
As the wipers are what might be considered a safety item, I re-wired them with their own fuse which is much safer.
My fuel pumps and headlights are relayed and all the circuits are fused independently.

[MiniBGT]

I had an electrical issue with my 1964 car a while ago. It was blowing one of the main 35 amp fuses. I managed to
isolate it to the wiper/fuel gauge circuit and stripped the speedo housing out. There was a bare connection on that circuit.
As the wipers are what might be considered a safety item, I re-wired them with their own fuse which is much safer.
My fuel pumps and headlights are relayed and all the circuits are fused independently.

Both my rally cars have all beams, spots, both fuel pumps, brake lights, horn, washers, wiper, and reversing light, relayed with individual fuses.  The MGB also has relays on the overdrive and Kenlowe fan.

[gazza82]

I had an electrical issue with my 1964 car a while ago. It was blowing one of the main 35 amp fuses. I managed to
isolate it to the wiper/fuel gauge circuit and stripped the speedo housing out. There was a bare connection on that circuit.
As the wipers are what might be considered a safety item, I re-wired them with their own fuse which is much safer.
My fuel pumps and headlights are relayed and all the circuits are fused independently.

Both my rally cars have all beams, spots, both fuel pumps, brake lights, horn, washers, wiper, and reversing light, relayed with individual fuses.  The MGB also has relays on the overdrive and Kenlowe fan.

That's what I'm intending to do but the question was are both "powered" circuits fused?? The main feed to power the relay is probably obviously yes as this takes the load, but it's whether the feed to the "switched" side is also fused. That is the 12v feed from the wiper/horn/etc switches?? Would you fuse the feed to the brake light switch circuit for example?

[Dusky]

I had an electrical issue with my 1964 car a while ago. It was blowing one of the main 35 amp fuses. I managed to
isolate it to the wiper/fuel gauge circuit and stripped the speedo housing out. There was a bare connection on that circuit.
As the wipers are what might be considered a safety item, I re-wired them with their own fuse which is much safer.
My fuel pumps and headlights are relayed and all the circuits are fused independently.

Both my rally cars have all beams, spots, both fuel pumps, brake lights, horn, washers, wiper, and reversing light, relayed with individual fuses. The MGB also has relays on the overdrive and Kenlowe fan.

That's what I'm intending to do but the question was are both "powered" circuits fused?? The main feed to power the relay is probably obviously yes as this takes the load, but it's whether the feed to the "switched" side is also fused. That is the 12v feed from the wiper/horn/etc switches?? Would you fuse the feed to the brake light switch circuit for example?

That should be fused as well. ( 2 fuses per relay, 1 on the power and one on the switch side).

[gazza82]

Thanks to everyone that responded .. my thoughts seemed to play out given the feedback .. ie two fuses.

Now to work out the size of those (micro blade) fuses .. :)