split relay charge

Duncan · Post by **Duncan** » Wed May 02, 2007 4:25 pm

wheres the best place to tap into the 12volts on/off alternator light.
I have wired to both my batteries from the relay as per instructions, and earthed the correct terminal, its just wiring to the alternator I am struggling with. I have found the plug in the side of the alternator that carries two wires, is it one of them ?

Cheers

Veg_Ian · Post by **Veg_Ian** » Wed May 02, 2007 4:27 pm

In theory it should be the thin one but if you do that it screws up the charge light resulting in the light glowing ie. you wouldn't know if you had a real fault or not. I put mine onto an ignition feed instead.

Duncan · Post by **Duncan** » Wed May 02, 2007 4:36 pm

Thanks for that, its the only bit i am not to happy about.

Duncan

madmile · Post by **madmile** » Wed May 02, 2007 9:34 pm

I must admit, the first few I did, I never had a problem with the charge light glowing, but now I have switched to the Tec3M voltage sensing relay - I know you can by them on ebay, towsure dont stock them anymore, but I think that 'indespension trailer centres' have them for about £15.

vanvliet · Post by **vanvliet** » Thu May 03, 2007 7:58 am

I sourced one of the TEC3M relays from Indespension and DandyD fitted it for me . Absolutely no problems - works a treat

dandywarhol · Post by **dandywarhol** » Thu May 03, 2007 12:08 pm

Who're you calling DandyD VanW.........

vanvliet · Post by **vanvliet** » Thu May 03, 2007 12:29 pm

D .It was early - hadnt showered or had the first coffee intake .

corblimey · Post by **corblimey** » Thu May 03, 2007 1:10 pm

As everyone else is suggesting; go with the TEC3M. It makes the job a piece of cake.

Here's my instructions.

mikeonb4c · Post by **mikeonb4c** » Thu May 03, 2007 1:57 pm

Corblimeys instructions (along the lines of Dandys design) made the job v simple for me - before that I just kept putting it off.

Duncan · Post by **Duncan** » Fri May 04, 2007 8:06 am

Yep as you said, connecting to the alternator works but leaves the light on slightly, this because the relay is drawing to much current and dropping the 12 volts to 7 volts. Being stubborn and not liking being beat I have added another relay to drive the split relay charger. this relay only draws 40 milliamps on the coil so the voltage does not drop. this relay then drives the contacts on the heftier split relay charger. happy to say it now works. Thanks for the imput.

Cheers Duncan

Veg_Ian · Post by **Veg_Ian** » Fri May 04, 2007 8:52 am

Well done Duncan, you've got more staying power than me. I'm afraid I give up too easily

waycar8 · Post by **waycar8** » Sat May 05, 2007 2:27 pm

thinking of swapping my winter pack to a single + leisure battery too.

just a quick question on split relays ect........after reading corblimeys fitting instructions and got looking for the said item and came a cross this

http://digitalsounddirect.co.uk/shop/pr ... d/907.html

just wondered if anyone had fitted this type before or if it will be ok as i intend to swap all the electricals on to the leisure battery

waycar8 · Post by **waycar8** » Sat May 05, 2007 2:48 pm

just came across this too

http://www.volkszone.com/VZi/showthread ... ge=2&pp=10
exuse my ignorance but...........if a normal relay will work from a mk1 or mk2 golf, whats the difference between this and a tec3m?(which i havent been able to source) as this is only a 30 amp and the golf one is a 40 amp

Mark & Shelly · Post by **Mark & Shelly** » Sat May 05, 2007 3:20 pm

Hows it going Wayne?
I think the Tec3 relay is a voltage sensing type, so it wont switch untill your main battery has got charged back up to capacity. These also stop the risk of your starter motor trying to draw current through your split charge circuit, which can happen if you wire an ordinary relay trigger to an + ignition/acc feed rather than the charging light(which is more complicated, & according to some sources not recommended for Jap vehicles).
When I did ours I tried to get away with a 30 amp relay, but found with a fairly flat leisure batt. & that 90amp bongo alternater I could blow fuses untill the cows come home.
Now I have a 100amp relay fused at 70amp, which is switched by a time delay relay connected to a convenient + acc feed, has anyone else gone down that route? seems to work a treat.

Duncan · Post by **Duncan** » Sat May 05, 2007 9:27 pm

I also think a time delay relay is a good idea. I still went with just the basic 35 amp split relay charger £10. Like I previously said though the only fault with this is the relay coil draws to much current and drops the 12 volts from the altenator. Because I work with some cleaver lads they provided me with a smaller relay to provide the voltage switch to the main relay. I did it this way because the relay was free and it works