Hi All,
I was having a look at the wiring to my alternator as it looks past its best. I want to replace some of the wiring but noticed that 1 of the crimp connectors at the alternator is a larger size than I have, the other connection is a much smaller size. What size is the large crimp connector and where can I buy replacements? Also what size will the wire to the alternator be? I also noticed the alternator has 3 terminals but only 2 are used - the large centre connection and the smaller connection - presumably this is correct?
What colour wire will go to the temp sender on the cylinder head and what colour to the oil pressure switch as these were disconnected and now I can't work out which is which - Doh!
Thanks in advance, Jeff
Connections to Alternator
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Hi Jeff. Oil filter warning & pressure switch was dark green. Temp gauge ws never fitted as standard so could be any colour that was used at the time it was wired up. If you have 2 dark green wires you will have to remove the earth wire from back of temp gauge and check for continuity to the ends of the two wires in engine or short one down to earth with ign on and see if oil light comes on. Not sure about terminal size for alt but prob about 5mm. Any motor factors should sell them... Rich
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The larger size Lucar should be readily available - even at Hellfrauds! And yes - there are two on the alternator but usually only one is used although you can double up to two if you wish. Electrically they are the same. As PSL suggests - just earth the sensor wires out - and see which lights come on! If you have an after-market temp gauge - earthing that wire will just send the gauge to HOT.
Last edited by bmcecosse on Tue Dec 02, 2008 7:22 pm, edited 1 time in total.
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IslipMinor
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The alternator sounds like one of the Lucas ACR range that has 2 'large' Lucar terminals, which each take the 9.5mm or 3/8" female connector (35A) and one 'standard' one, which takes the 6.3mm or 1/4" connector (17.5A). Both push-on connectors are very available from motor factors.
Whether you use one or both of the large connectors really depends on the alternator output. What size is yours?
Up to around 35A, you can use just one terminal with a wire size of 65/0.3mm (4.50 sq mm), but this is the maximum rating of the large Lucar connector. Above 35A you should use both large connectors with either 44/0.3mm (3.00 sq mm) wire from each for up to 50A, or 2 x 65/0.3 up to 70A.
Using a smaller than recommended wire size can cause a significant volt drop, which equals heat in the wire and at the connections - not a good idea!
For the main alternator connections soldered joints to the push-on connectors are better than crimped, and the same for the ring connector on the starter solenoid.
Whether you use one or both of the large connectors really depends on the alternator output. What size is yours?
Up to around 35A, you can use just one terminal with a wire size of 65/0.3mm (4.50 sq mm), but this is the maximum rating of the large Lucar connector. Above 35A you should use both large connectors with either 44/0.3mm (3.00 sq mm) wire from each for up to 50A, or 2 x 65/0.3 up to 70A.
Using a smaller than recommended wire size can cause a significant volt drop, which equals heat in the wire and at the connections - not a good idea!
For the main alternator connections soldered joints to the push-on connectors are better than crimped, and the same for the ring connector on the starter solenoid.
Richard
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Jefftav
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alternator connections + heated screen wiring
Hi All & Happy New Year.
I have done as suggested and upgraded the wiring from the alternator taking off two large wires and one small one using a plug in kit arrangement. I have taken one large wire to the connection of the wire I am replacing which leaves another large wire to go where?
The existing connection just goes into a connector block is there any better way of doing this as it looks a bit of a mess and possibly asking for trouble in the future.
I also intend to have a heated front and rear screen would anyone have a wiring diagram to show how to connect up the relay and switch for each screen.
Cheers and thanks, Jeff
I have done as suggested and upgraded the wiring from the alternator taking off two large wires and one small one using a plug in kit arrangement. I have taken one large wire to the connection of the wire I am replacing which leaves another large wire to go where?
The existing connection just goes into a connector block is there any better way of doing this as it looks a bit of a mess and possibly asking for trouble in the future.
I also intend to have a heated front and rear screen would anyone have a wiring diagram to show how to connect up the relay and switch for each screen.
Cheers and thanks, Jeff
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IslipMinor
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Jeff,
There should not be any connector blocks; both the large wires from the alternator go directly to the battery side of the starter solenoid, or pull switch (they are 'joined' only at this point). The small wire is for the ignition warning light circuit.
If you have to join them earlier, then make a three-way soldered joint and use 2-3 layers of heat shrink insulation to give physical protection against chaffing.
There must be no risk of this alternator wiring connecting with the body, engine or similar part, as it is connected directly to the battery through a heavy cable that will not 'fuse' if it touches.
Just a thought - are you planning to fit an ammeter? This will affect the routing of the wires from the alternator.
There should not be any connector blocks; both the large wires from the alternator go directly to the battery side of the starter solenoid, or pull switch (they are 'joined' only at this point). The small wire is for the ignition warning light circuit.
If you have to join them earlier, then make a three-way soldered joint and use 2-3 layers of heat shrink insulation to give physical protection against chaffing.
There must be no risk of this alternator wiring connecting with the body, engine or similar part, as it is connected directly to the battery through a heavy cable that will not 'fuse' if it touches.
Just a thought - are you planning to fit an ammeter? This will affect the routing of the wires from the alternator.
Last edited by IslipMinor on Fri Jan 02, 2009 9:42 am, edited 1 time in total.
Richard
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IslipMinor
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Not sure what the 2 brown/green wires are for? The original dynamo main feed was brown/green, but only a single wire. What are they connected to?
Do you still have the dynamo control box connected, if so how?
Do you have any pictures?
'Normally' the feed(s) from the alternator are plain brown and go directly to the starter solenoid/ pull switch.
Do you still have the dynamo control box connected, if so how?
Do you have any pictures?
'Normally' the feed(s) from the alternator are plain brown and go directly to the starter solenoid/ pull switch.
Richard
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Jefftav
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Hi Islipminor, The regulator has been removed. Hopefully I have added so pictures or the links to them? The connector block has the large red wire which is from the alternator (3rd pic), the solenoid has 1 brown wire from this connector block (1st Pic) and another smaller white/red wire (2nd pic) but not sure what that does. Any advice is welcome as I would like to tidy up the wiring and remove connector block if possible. Eventually I want to have my heated front and rear screen working and was going to run another large wire from the 2nd connection on the alternator but can't decide if I should connect it straight to the battery on solenoid?
Thanks Jeff
Thanks Jeff
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IslipMinor
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Jeff,
Do you know what output your alternator has? If it is a Lucas unit there should be a small aluminium tag with the model type on it. Like 15ACR etc.
The 'bog standard' unit fitted was the 15ACR, which had an output of 27A and could just about use the standard dynamo wiring, but not if the full output is going to be used for long periods of time (e.g. lights and heated screen(s)), and all the rest definitely need the wiring to be upgraded.
I am making one assumption - that the original wires are still being used for the original purpose!
Easy one first, the white/red is the feed from the ignition switch in 'start' position to the starter soledoid for the starter motor. Nothing to do with the alternator.
There was only one brown/green wire used as 'original' and that went from the dynamo output to the regulator box. Can you see where your 2 brown/green wires go?
If everything is working as now wired, you could run a 'new' wire from the second alternator terminal directly to the 'battery' side of the starter solenoid. The wire size should be a minimum of 35/0.3mm (2.5 sq mm) to be sure that it can take the load. Make the connection on the starter solenoid with a ring terminal on to the same post as the wire going to the battery, not a second connection on to the existing push-on terminal. You can get a large push-on connector with a ring terminal to fit on to the battery wire terminal, and then use a large push-on connector on the wire from the alternator.
Any accessories should be wired from the battery connection on the solenoid, via a fuse then a relay, which will be triggered either by a switch fed via a fuse from the ignition switch, or a switch fed via a fuse from a 'non-ignition' source. New feeds should be fused before the switch and anything such as heated screens should be fed via a relay, with a fuse in the supply to the relay.
You could use a feed from the battery connection on the starter solenoid to feed an additional fusebox to provide the supply to your new accessories. You will still need to separately fuse the supplies to the new switches (presumably most will be fed from the ignition switch?).
Do you know what output your alternator has? If it is a Lucas unit there should be a small aluminium tag with the model type on it. Like 15ACR etc.
The 'bog standard' unit fitted was the 15ACR, which had an output of 27A and could just about use the standard dynamo wiring, but not if the full output is going to be used for long periods of time (e.g. lights and heated screen(s)), and all the rest definitely need the wiring to be upgraded.
I am making one assumption - that the original wires are still being used for the original purpose!
Easy one first, the white/red is the feed from the ignition switch in 'start' position to the starter soledoid for the starter motor. Nothing to do with the alternator.
There was only one brown/green wire used as 'original' and that went from the dynamo output to the regulator box. Can you see where your 2 brown/green wires go?
If everything is working as now wired, you could run a 'new' wire from the second alternator terminal directly to the 'battery' side of the starter solenoid. The wire size should be a minimum of 35/0.3mm (2.5 sq mm) to be sure that it can take the load. Make the connection on the starter solenoid with a ring terminal on to the same post as the wire going to the battery, not a second connection on to the existing push-on terminal. You can get a large push-on connector with a ring terminal to fit on to the battery wire terminal, and then use a large push-on connector on the wire from the alternator.
Any accessories should be wired from the battery connection on the solenoid, via a fuse then a relay, which will be triggered either by a switch fed via a fuse from the ignition switch, or a switch fed via a fuse from a 'non-ignition' source. New feeds should be fused before the switch and anything such as heated screens should be fed via a relay, with a fuse in the supply to the relay.
You could use a feed from the battery connection on the starter solenoid to feed an additional fusebox to provide the supply to your new accessories. You will still need to separately fuse the supplies to the new switches (presumably most will be fed from the ignition switch?).
Richard