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Starter fuses
prawnabie - 1/10/08 at 10:36 PM

My "ignition" fuse box is energized by a relay that is switched by the ignition barell.

Terminal 85 is the feed from the barrel
Terminal 87 is the feed to the "igniton" fusebox
Terminal 30 is a permanent live from the battery connection to the starter.
Terminal 86 is obv. earth.

Do I need to fit a fuse between terminal 30 and the connection to the battery connection on the starter.

Do I also need to fit a fuse between the ignition barrel and the same connection as above.

Thanks

Shaun

Mr Whippy - 2/10/08 at 07:05 AM

yes, fit one fuse close as possible to the battery. I'd use 30 amp wire with a 20 amp fuse. It would also be a good idea to fit a 30 amp switch to it before the ignition barrel, hide it somewhere or on the dash incorrectly marked (like front fog lights) and use that as a simple imobilizer

adithorp - 2/10/08 at 07:37 AM

I don't know the contact numbers off the top of my head but yours don't sound right.

You should have...

1. 12v feed in (from battery).
2. Accesory feed out (live in position 1+2).
3. Ignition feed out (live in pos' 2+3).
4. Starter feed out (live in pos' 3 to starter solenoid)

There's no earth contact!

adrian

Mr Whippy - 2/10/08 at 08:04 AM

quote:
Originally posted by adithorp
I don't know the contact numbers off the top of my head but yours don't sound right.

You should have...

1. 12v feed in (from battery).
2. Accesory feed out (live in position 1+2).
3. Ignition feed out (live in pos' 2+3).
4. Starter feed out (live in pos' 3 to starter solenoid)

There's no earth contact!

adrian


I think in this instance he is using a switching relay much like that used for spot lights and the like to activate the starter solenoid, hence the odd numbers. My Nissan has this too so the ignition barrel isn't having to handle the high current for operating the starter solenoid. It’s quite common on modern cars, in the old days the barrel switch had some quite meaty wires going to it but that just tended to burn the contacts. Make sure the relay is rated for at least 30 amps and that the fuse is rated for less than this, see diagram below -

Image deleted by owner



[Edited on 2/10/08 by Mr Whippy]

adithorp - 2/10/08 at 08:16 AM

Ahhh...must learn to read the post properly!

adrian

Macbeast - 2/10/08 at 08:42 AM

You don't fit a fuse in the feed to the large terminal on the starter, which can take hundreds of amps. Only in the feed to the small solenoid terminal as above ^^^^

You probably know this but just in case

Mr Whippy - 2/10/08 at 09:14 AM

quote:
Originally posted by Macbeast
You don't fit a fuse in the feed to the large terminal on the starter, which can take hundreds of amps. Only in the feed to the small solenoid terminal as above ^^^^

You probably know this but just in case


you can fit one quite easly if you want, handy if you ever had the cable break and touch the engine block or chassis, like in a crash for example, might prevent a fire or even the battery exploding

these fuses are available in 200 amps, 300 amps, 400 amps, and 500 amps and are a doddle to fit.





[Edited on 2/10/08 by Mr Whippy]

Macbeast - 2/10/08 at 01:12 PM

I stand corrected

prawnabie - 2/10/08 at 09:00 PM

Said the man in the othopedic shoes!

Sorry had to do it!

Thanks for the replies.

gazzarose - 2/10/08 at 09:59 PM

I work in a boat shop and on most of our engines (mostly american V8s) theres a fusible link on the main starter terminal. Ive also used those fuses above when fitting bow thrusters which take alot of amps (80 + depending on the boat) and they are easy to fit (if you were rero fitting youd need a short length of cable with a couple of ring terminals).

Gazza

prawnabie - 3/10/08 at 10:19 AM

Sorry I think I have give everyone the wrong idea!

I have a fuse box that is energized by a relay controlled by the starter switch. This fuse box is only on when the igntion is on.

The main feed for the relay/fuse box comes from the perm live post on the starter.

obviously everything connected to that fuse box is fused, but the relay that energises the actually fuse box isn't. Would I need to fit a fuse in between the relay and the terminal on the starter?

Sorry for the confusion!