Guest diesel_jim Posted June 30, 2008 Share Posted June 30, 2008 On my old 300Tdi i had a main battery cut out switch, which killed everything (apart from the alarm, which was an aftermarket pihrana one that i wired in, and wired it in such a way that it could work the hazards etc with the battery turned "off") i'm wondering if its a good idea or not for a Td5? i can't imagine the ECU will forget it's name or where it lives without power for a week or 3, just wondering if there's a way i can keep the alarm working properly?? Quote Link to comment Share on other sites More sharing options...
western Posted June 30, 2008 Share Posted June 30, 2008 Would one of the FIA type isolators work. as it has a connection for alarm & stuff with memory. Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted June 30, 2008 Share Posted June 30, 2008 Would one of the FIA type isolators work. as it has a connection for alarm & stuff with memory. What's one of those then Ralph? not seen one.... Quote Link to comment Share on other sites More sharing options...
western Posted June 30, 2008 Share Posted June 30, 2008 has the large main isolator connections as any normal isolator & 2 pairs of spade connectors for stuff that always needs a 12v feed. this one have you not seen them before Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted June 30, 2008 Share Posted June 30, 2008 has the large main isolator connections as any normal isolator & 2 pairs of spade connectors for stuff that always needs a 12v feed. this one have you not seen them before ahhh yes.... i thought they just did the alternator, nothing else. i'll look into it and see what i can fiddle with. Quote Link to comment Share on other sites More sharing options...
western Posted June 30, 2008 Share Posted June 30, 2008 I'm sure you can find a work around to make it do what you want. Quote Link to comment Share on other sites More sharing options...
Escape Posted July 1, 2008 Share Posted July 1, 2008 On my old 300Tdi i had a main battery cut out switch, which killed everything (apart from the alarm, which was an aftermarket pihrana one that i wired in, and wired it in such a way that it could work the hazards etc with the battery turned "off")i'm wondering if its a good idea or not for a Td5? i can't imagine the ECU will forget it's name or where it lives without power for a week or 3, just wondering if there's a way i can keep the alarm working properly?? I wouldn't risk it, to be honest. I have not heard of problems with a TD5, but I now there is a continuous power usage, caused amongst others by the ECU. On a P38a, prolonged lack of power, can leed to the loss of adaptive values and even the death of the ECU. Why are you considering a cut-off? As an emergency measure or rather as an (additional) anti-theft device? Quote Link to comment Share on other sites More sharing options...
mmgemini Posted July 1, 2008 Share Posted July 1, 2008 I wouldn't risk it, to be honest. I have not heard of problems with a TD5, but I now there is a continuous power usage, caused amongst others by the ECU.On a P38a, prolonged lack of power, can leed to the loss of adaptive values and even the death of the ECU. Why are you considering a cut-off? As an emergency measure or rather as an (additional) anti-theft device? Well the competition boys are fitting TD5 engines. Even using TD5 Defenders. They have to have one fitted so they are fittable. mike Quote Link to comment Share on other sites More sharing options...
ltwt1981 Posted July 1, 2008 Share Posted July 1, 2008 Its fitted as a safety device, if you roll or crash the marshalls can cut the power. You don't have to turn it off when parking up, so if you are worried about ECU's etc leave it on. You'll fail scrutineering if it doesn't cut out everything anyway. Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted July 1, 2008 Share Posted July 1, 2008 Could you not measure the current consumption of the ECU etc with everything switched off and then install a suitably rated (i.e low) fuse that bypasses the cut off switch to keep them powered up, but being a low current rating would blow if someone tried to start the vehicle without de-isolating the batteries. Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted July 1, 2008 Share Posted July 1, 2008 Could you not measure the current consumption of the ECU etc with everything switched off and then install a suitably rated (i.e low) fuse that bypasses the cut off switch to keep them powered up, but being a low current rating would blow if someone tried to start the vehicle without de-isolating the batteries. Good idea that. might well do that, also it'll mean the alarm will still be active. Why are you considering a cut-off? As an emergency measure or rather as an (additional) anti-theft device? bit of both really. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted July 1, 2008 Share Posted July 1, 2008 There will be no problem with it forgetting alarm codes etc if powered down for a long period Quote Link to comment Share on other sites More sharing options...
Escape Posted July 1, 2008 Share Posted July 1, 2008 Well the competition boys are fitting TD5 engines. Even using TD5 Defenders. They have to have one fitted so they are fittable.mike Don't get me wrong, I own and love a TD5! I also don't have a problem disconnecting the battery (although on a few occasions this has lead to the alarm going off ), it's just that leaving it cut off for weeks doesn't seem like the best idea. I have seen an ECU (not TD5) killed that way, and just to be safe, I'm keeping the one in my RR under power even during the engine rebuild (alternator and such is cut off, naturally). Quote Link to comment Share on other sites More sharing options...
Litch Posted July 4, 2008 Share Posted July 4, 2008 The spade connectors onm the rear of an FIA switch are not to provide auxilary power, one pair is for the supply to the ignition / fuel solenoid and the other pair are for the balast resistor (to prevent alternator damage). When one pair of terminals is 'closed' the other are 'open and visaversa. Having said that, to add an auxilary supply which is always live is very easy as you just take it from the battery (non-switched) side and fuse it accordingly. I have been using these switches in that way for over 20-years now, they work perfectly and are very reliable. Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted July 5, 2008 Share Posted July 5, 2008 With the ignition off, there is no power to the ECU anyway. So I forsee no problems with a cut-off. And they sit quite happily on a shelf in the storeroom without anything going wrong with them. Quote Link to comment Share on other sites More sharing options...
smo Posted July 5, 2008 Share Posted July 5, 2008 With the ignition off, there is no power to the ECU anyway. So I forsee no problems with a cut-off.And they sit quite happily on a shelf in the storeroom without anything going wrong with them. Likewise my D-Lander's TD5 ECU and alarm unit are removed for prolonged periods of time without problem. The biggest one to watch on the TD5 is the alternator, hence the ballast resistor. Quote Link to comment Share on other sites More sharing options...
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