Fuses and wiring.

[deltalimamike]

The fuses on the bulk head of a 1.5 are 35amp I believe?

I'm referring to the permanent live and ignition live that sit next to the voltage regulator.

If so, the wires supplying this should be quite thick shouldn't they, whilst mine look reasonable they don't seem overly substantial however they look "original" , am I getting confused (again)?

[canuck]

Hello Mike,
No confusion. FWIW I think a 2 fuse electrical system, although period correct, is dicey so we need to treat this with care. Cleaning the bullets and connectors after all these years is good practice. Re assemble the bullet/connector with a smear of dielectric grease for good measure.  These connectors can become brittle over time, (a bit like us  )  so ensure if you do play with these that the metal connection bit is intact. If not renew, and these are not expensive. Usually sold in a 10 pack.



As well it is prudent to check the screws at the control box for any 'green' corrosion and clean these terminals, tighten with a smear of dielectric grease as well.  The earth points probably should receive a bit of loving as well. Clean & grease to be sure.



So to come back on topic of fuses, have another look Mike, these fuse are 'special'. 

As I understand this 35 amp is the full rating for the 35 amp Lucas fuse is - “17 AMPS CONTINUOUS / 35 AMP SURGE or MAXIMUM”. A surge fault at 35 amp will definitely blow the fuse. A slow load at >17 amp will also blow the fuse.

So the fuse is (35 amp ) often marked as “17 continuous / 35 blow”, or simply 17/35.





In this case, use the lower “continuous” rating as the one to which you try to match the line load. In the two fuse block, I maintain these 17/35 fuses.

You can fit American type BUSS rating, or the general purpose AGC type @ 20 amps rating without fear of letting smoke out of the harness.  Of course one should never fit an American BUSS or AGC @ 35 amp fuse.

So, best and safest to use the 17/35 slow blow Lucas OE type. Nice to keep things totally British as well, no?

FWIW I installed a few more circuits in my car, to ease the loads of the original fuse box.

1) Driving lamps relay, 2) headlamps relays and 3) an accessories circuit.

I used a simple in line fuse holder and fitted the fuse,(AGC type) from Autosparks to suit the particular circuit load.





The ‘slow blow’ fuses are readily available so no need to get creative.



www.durite.co.uk/itm/54984/32mm-Flat-Ended-Glass-Fuses/32mm-Flat-Ended-Glass-Fuse-175A-Continuous-35A-Blow/037435


B

[deltalimamike]

Thank you.

It would seem a previous owner didn't ask a similar question before changing this fuse then as it's not the one you describe.

I do have separate circuits for headlights and an electric radiator fan so at least they are separate and on their own circuits (albeit I'm still not overly happy with them).

I'm in the process of checking and removing any old wiring that is not needed (there's seems to be a fair amount for various additional fitments over the years) and I'll then probably re-wire where I'm not happy (hence the original question about the wiring to the bulk head fuse (it's not in great shape)).

I have a new Lucas items for the fuse and regulator so I'll also replace those.

Thanks again for your reply, if you think I'm going about things wrong I'm happy to take feedback!

[canuck]

Welcome Mike

The only other advice I can offer is to use correct style, colour  and gauge wire for the application. (below) 


If possible follow the factory wiring schematic, which by the way is pretty simple on these cars. 
The correct colours of the old braided type wires on our cars is available. You can have solder bullets and connectors to make everything look as it should and be reliable. 
Below is the best source IMO and FWIW I buy my electrical components from them and have it posted over to this side of the pond. I have never been disappointed with the quality or service.

www.autosparks.co.uk/electrical-components/cables/braided.html

www.autosparks.co.uk/electrical-components/bullets-connector-sleeves/crimp-or-solder-bullet-to-suit-braided-9-0-30-cable-price-per-10.html

Do you still have a positive dynamo installed? If so you might reconsider changing out the control box? If the electrical system is charging as should then you will save yourself some work not having to calibrate the new control box. This calibration is not difficult but needs to be done correctly.   I agree, a new fuse box can only be a positive swap. 

As I mentioned I added some extra circuits to my car. I chose to use in-line fuses, added early in the circuit. (below) Remember that fuses protect the wiring not the component.  




Have fun

Bruce

[deltalimamike]

Thanks again Bruce.

We are on negative earth and alternator now.

I understand what you mean about the control box but for some reason I quite like the look of it and don't really want to lose it.

I'm ok with the calibration, have read up on that.

That said I may change my mind by the time I get to look at the part of the wiring.

I'll investigate that website 😁 and report back on progress.

[deltalimamike]

Oh and looking at your picture my wiper motor is not the correct one either.

[canuck]

May 21, 2019 17:47:47 GMT deltalimamike said:

Oh and looking at your picture my wiper motor is not the correct one either.

Mike
Different motors may have been fitted by previous owners. 
Post a photo of your windscreen wiper motor, perhaps we can identify it?

The original type, Lucas DR3 as shown in my photo was very common in BMC cars of this era. This DR3 model is a simple 1 speed,  park right/park left motor. 

B

[deltalimamike]

May 22, 2019 17:38:11 GMT canuck said:

May 21, 2019 17:47:47 GMT deltalimamike said:

Oh and looking at your picture my wiper motor is not the correct one either.

Mike
Different motors may have been fitted by previous owners. 
Post a photo of your windscreen wiper motor, perhaps we can identify it?

The original type, Lucas DR3 as shown in my photo was very common in BMC cars of this era. This DR3 model is a simple 1 speed,  park right/park left motor. 

B

It's a bit of an old photo but it's this one.

[canuck]

Mike 

Interesting. Is this motor a single speed? What do the electrical connections look like? Simple wire terminals or a plastic plug? Any numbers on the gearbox cover? (below)



I assume when the switch to negative earth was done the wiper motor was changed out?

B

[deltalimamike]

Yes it's single speed.

No plastic plugs or anything.

I'll get some better pictures when I'm working on the car next time and see if there are any more clues on the casing.

It works ok, not that i take the car out in the rain as the windscreen rubbers are like sponges and I'm sure are leaking and the water also comes in around the bonnet hinge I think.