Where to run wiring

bonerp · Post by **bonerp** » Sun Apr 10, 2011 9:12 pm

i'm putting a big fuse on the alternator and on the battery. Think I've got 60 mega blade fuse and some other kind. Will dig it out during the week.

I put a relay on the headlights and the horn. Theres another for a heated screen.

threefiftysix · Post by **threefiftysix** » Tue Apr 12, 2011 9:35 pm

Bear with me on this one, I may well be being a bit thick.

If I put a fuse in the wire between the battery and alternator, it will protect the alternator / battery circuit, but given that all the battery cables meet at the starter motor, there is still unfused power running from the battery via the starter terminal and then on to the ignition switch, through the switch and on to the coil etc. Is this a problem?

Two questions - I assume a fuse between battery and starter motor would be pointless due to massive current draw? Secondly, would adding a fuse in the power wire from the starter terminal to the ignition switch be sensible? If so, anyone care to calculate the ampage?

Apologies if the electricians amoung you are shouting at your screens by now, I just want to avoid smoke when I turn the ignition switch

mdmax72 · Post by **mdmax72** » Tue Apr 12, 2011 10:06 pm

This guys was mechanical but same ending, not alot left after a fire. Like in a sad way how the fire crew much have gone to the bonnet to put the fire out by the looks of it.

http://www.youtube.com/watch?v=ZYMZfqFwh2A

threefiftysix · Post by **threefiftysix** » Wed Apr 13, 2011 9:25 am

Thanks, Rich. Just the confidence boost I need with this wiring

Carb fires in fiberglass cars are something else that has been praying on my mind. I just managed to rescue a previous GRP bodied car when one of the twin 45s decided to flambé itself. Have been considering fuel injection for this very reason, but the cost is quite prohibitive at the moment for me. Although saying that I guess it is uber reliable and in theory fit and forget, unlike carbs.

Anyhow, sorry again, thread drift. Would still appreciate the views of anyone knowledgeable on electrics with regards to the fuses. Cheers.

bonerp · Post by **bonerp** » Wed Apr 13, 2011 9:50 am

might be a bit OTT but I also bought an isolator that also isolates the alternator. Look on Premier Wiring or such like for these. Cost about £18.

There are a couple of threads on this forum going back a while where fires have caused meltdown as well as the sad You Tube video Rich added - if its the one where he provides a quick excited run down with some heart wrenching music until the fire started....can't see this at work.

I'm sure I was going to do battery to starter as well tho....!

Good reason for adding cheap relays tho.

http://www.ddk-online.com/phpBB2/viewto ... fuses+fire

http://www.ddk-online.com/phpBB2/viewto ... fuses+fire

mdmax72 · Post by **mdmax72** » Wed Apr 13, 2011 10:15 am

Sorry to dash your confidance. Not no auto electrician, but i'd agree with you on the 1st question.
The 2nd one, your ignition circuit should already be covered by a fuse in your fuse block. Will properly cover a few other things also. You could put an inline fuse in but if you get carried away fitting fuses everywere, when one blows would be a bitch finding the blown one. Just checked my bible and ignition circuit amp is 1.5-4amps.

Picture 1 is of the ignition circuit and no2 is the starter circuit. Hope this helps or gives you the confidence back i've just robbed

Carb fire is normally connected to timing or valves not set right..

bonerp · Post by **bonerp** » Wed Apr 13, 2011 10:22 am

I don't believe the Pilgrim fuse exists.circuit properly protected hence the need for additional circuitery.

The isolator will only help when setting the car up as it will break the link between charge and circuit, unless you place it in the passenger compartment. Also disconnects the alternator which will hold charge for longer than the circuit when the ignition is off.

threefiftysix · Post by **threefiftysix** » Wed Apr 13, 2011 4:12 pm

Thanks Rich. From the diagram the coil ignition circuit does not run through the fusebox, but has direct battery power through the ignition switch to the coil. I better add a fuse to this circuit and one for the alternator and hope all is well.

Thanks all. I don't really want to see any more fried 356s thankyou...

bonerp · Post by **bonerp** » Sun Apr 17, 2011 4:35 pm

im struggling with engine bay wiring...

On the alternator there is a 12v post for the battery lead and the charge light, and another 3 terminals marked Df, D- and D+.

Can anyone help with wiring this bit as i'm not sure?

thanks

mdmax72 · Post by **mdmax72** » Sun Apr 17, 2011 5:13 pm

I've only got 2 terminals on my alternator.
B+ for the charge and D+ for the other if that's any help.

threefiftysix · Post by **threefiftysix** » Sun Apr 17, 2011 6:44 pm

Hi paul,
My alternator only has the ring terminal for the charge lead and a spade for the warning light. Does your alternator have an external regulator by any chance? It sounds as though they could be connections to a regulator?

I worked out the dynamo vs alternator wiring in the loom yesterday - quite straight forward, i removed the two short brown link leads in the main charge wire and connected the two wires together if you see what i mean. I took the blue and black dynamo lights out of the loom all together.

I also realised all the wiring is in the loom for the headlight relay - they just don't bother putting a holder in for it, which is helpful.

Sorry you are having trouble - I managed to get the engine hooked up and all the dash switches today - all suprisingly easy (as i have a simple alternator

), so don't panic when you get to the bunch of wires under the dash. There are two faults in the diagram though - i am positive of it. The fog light feed switch is actually solid blue, not as shown, and the wires for the flasher described as light green / brown are dark green / brown on mine. Nothing major but i wasted half an hour tracing the wires through the loom to make sure.

bonerp · Post by **bonerp** » Sun Apr 17, 2011 7:22 pm

yeah i'm thinking it needs an external regulator. Better start trawling VWHeritage again.
here it is...

I noticed a couple of errors with the colour of wires when marking up. Fairly straight forward to trace through - just annoying as you say takes extra time.

Not a clue on the alternator wiring but connecting to dynamo wire kinda matches what the wiring diagram says. I'll be amazed if Kev ever starts lol

cheers

bonerp · Post by **bonerp** » Thu Apr 21, 2011 6:52 pm

quick question-I've bought a battery cut off switch with the extra poles for ignition and stopping surges. I dont get it though...

The main switch is for the battery cut off - ok with this. Switch 1 is a run off from the main power to one side of the switch and on the other side to a resister to earth - I dont get this! Can someone explain how this works?

Switch 2 is ignition cut off to the coil - I get that.

http://www.holden.co.uk/productimagesWD/020_011.jpg

thanks

Paul

bonerp · Post by **bonerp** » Thu Apr 21, 2011 10:00 pm

SOLVED! A good explanation here for anyone else:

http://www.pegasusautoracing.com/pdfs/4 ... ctions.pdf

threefiftysix · Post by **threefiftysix** » Sat Apr 23, 2011 7:16 pm

A couple of questions;

There is a wire which comes off the coil which goes to an automatic choke - I assume twin webers don't have this? I can't find anything that looks like it has an electrical connection on the carbs?

Secondly the wire feeds an 'anti run on valve' any ideas what this Is? Do I need one?