| Author | Message | ||
     Randy Roberson Grand Master Username: wascator Post Number: 549 Registered: 5-2009 |
Finally got an assistant (Igor, otherwise known as the family college student) to assist: I could hear a distinct clunk-click when I reconnected the battery ground in the boot but it was at the other end of the Car and I could not be at both places. Condensed version: the sound comes from inside the Car underneath the dash on the driver's side. It could be a relay but it sounds just a little more substantial: not quite a clunk, but more than a click. Is this a normal sound or is this possibly the source of my battery drain? Nothing was on at the time save the clock which does work by the way. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 710 Registered: 5-2015 |
My car clicks from behind the dash as well. How many milliamps is the drain? | ||
| Randy Roberson Grand Master Username: wascator Post Number: 550 Registered: 5-2009 |
That is my next measurement. | ||
| gordon le feuvre Frequent User Username: triumph Post Number: 94 Registered: 7-2012 |
It is worth taking all fuses out, then replacing one by one but remember that replacing interior will spike if door is open for access to fuse box!! On Shadow 11 I understand acceptable drain should be about 10-20 millamps?. The only standard fitments that draw power are the clock and radio memory dependant on model fitted. Is it late after market etc. Is there immobilsiser/alarm fitted, fused other than through fuseboard. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1013 Registered: 5-2012 |
I'm watching this thread with interest as I have the same problem on SRX18501. I am currently living with the problem, by isolating the battery with the cutoff switch I fitted a while ago, when I leave parked up for any length of time. The drain is 800 mA. I have checked all the obvious things like the glove box light etc and have also removed all the fuses, one by one, to no avail. I always get the 800 mA reading whichever fuse is removed. Since I've replaced the starter motor a few months ago, I am not expecting leakage from oil and crud in that area as it was well cleaned when I replaced the motor. I will check however, just in case. The one test I have not yet carried out is to turn the power on from the isolator switch in the boot, with an assistant in the car with the doors closed, to detect any clicks from relays or movement of the ammeter needle. Next step will be to check the wiring against the wiring diagram utilizing all the clues I have gleaned from the work so far. Randy - I would be grateful if you could let us know how you get on in tracing the fault on your car. Geoff. | ||
| Jim Walters Experienced User Username: jim_walters Post Number: 47 Registered: 1-2014 |
The most common battery drain we find is a bad diode in the alternator. One diode can leak but the alternator will still charge fine. A tell tale is a high pitch whine in your radio speakers corresponding to engine RPM's. The first thing we always do when looking for a drain is to unplug the alternator, 9 times out of 10 that is it. SRE22493 NAC-05370 www.bristolmotors.com | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 716 Registered: 5-2015 |
Alternator diode failure is common to any alternator. Place a ammeter between the alternator and the fat wire (Brown if Lucas). Engine not running. If ammeter not available then a bulb in series will light if diide has failed. A diode that has failed and is conducting both ways also puts AC current into the system. In general car electrics will not be damaged. But the battery will be damaged eventually. Diodes that fail ooen circuit both ways will not discharge the battery. However the alternator output will be down. The regulator will compensate by increasing the rotor field voltage. But if a heavy load is placed on the alternator the missing phase will cause vibs and max output to be lower by quite a bit. If a fuse is removed and a light bulb placed across the fuse board. If the bulb lights that fused cicuit is drawing power. There is an isolator switch that also automatically turns off if battery voltage falls below a set level. Usually 12.4 volts. But this is treating the symptoms not the cause. My car clock is mechanical with a solenoid that winds the main spring every min. The multimeter flicks. The radio memory is about 5ma. I guessimate average is 20ma. Recently I tried to run the clock on a PP9 battery. Unfortunately no go. I did muse a rechargeable drill battery to run clock and radio memory. The battery would last for ages before recharging. Turning off the isolator isn't a problem but radio memory and time clock is irritating. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 551 Registered: 5-2009 |
Far as I can tell the radio is original (works) and there is nothing added. The alternator and starter were just reworked at a reputable local shop, but not because of this. I think this may have been a problem with the PO now deceased as it had a cutoff switch fitted. It was clumsy so I removed it and I disconnect the ground at the battery: same effect. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 717 Registered: 5-2015 |
The starter can't really cause a drain. Important that the drain is measured. The amount gives a clue. Example 1 amp drain is 12watts and a lot. 100 ma is 1.2 watts or a small light bulb. Error. My car doesn't click when reconnecting battery it only clicks when ignition is turned on. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1015 Registered: 5-2012 |
Jim Many thanks for your suggestion. It certainly was a very good possibility but alas, on disconnecting the alternator I still have the drain. I fear this fault is going to take some time to find. I will work backwards from the alternator, starting with checking out the regulator. Before this though, it occurs to me I have never replaced the diodes in the fusebox. Maybe that would be the next thing to try. The drain is a steady 670 mA. Geoff | ||
| Jim Walters Experienced User Username: jim_walters Post Number: 48 Registered: 1-2014 |
Geoff, I'm sure you have checked that the door and boot lamps are extinguishing also? 670 mA @ 12 volts is 8 watts which is a lot relatively speaking. Sounds like a light bulb but check the fuse panel diodes too. I would expect a diode to be warm with that amount of power running through it if it was shorted. SRE22493 NAC-05370 www.bristolmotors.com | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1016 Registered: 5-2012 |
Jim Thanks again for your help. I am sure all light bulbs are extinguished but I will double check just to be absolutely sure. I have already removed all the fuses to no avail. Since all light bulbs are fused, this acts as a double check against the possibility I have missed one. My next check will be to replace the diodes on the fuse panel. I like your tip about seeing if any are warm - it might take me straight to the defective diode, if the fault is with them. Geoff | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 721 Registered: 5-2015 |
Remove the gearchange relay. Then test. Just a thought. The idea of checking for hot diodes is good. Have you go a lazer dot temperature gauge. Only 20 quid. Many other uses as well. | ||
| gordon le feuvre Frequent User Username: triumph Post Number: 95 Registered: 7-2012 |
Another obscure one I seem to remember was water leaking into door pillar switches causing interior light delay unit to bring/hold on interior lights for an intermittent? period. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 727 Registered: 5-2015 |
On car SOS they had a Porsche 911 that had a leaky windshield seal. The water caused the seat electrics to short out and catch fire. I didn't think water and 12v was dangerous. The problem with fuses and circuit breakers is that they allow slow shorts that are just under the threashold. Of course being seat motors the normal current consumption is quite high. So a 25 amp short won't blow a 30 amp fuse. But a 25 amp short is 300 watts which is enough to start a fire. I can't think of solutions except keep a wary eye out for water where it shouldn't be, and use the isolator. Back to square one so to speak. Note I am not entirely convinced that water and 12v caused the Porsche fire. The loom could have got caught in the seat mechanicals. Its difficult to tell from a burned up loom. 12v and water and electronics will cause malfunctions like interior light delay circuit switching at random, not so sure about fires. The click from behind yhe dash sounds like a relay. The relay coil doesn't use 700ma, so I suspect the relay is turning something on. On my SS1 17768 just above the drivers kick panel are 2 fuses. I have no idea what they do. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 728 Registered: 5-2015 |
The battery is connected directly to the starter motor solenoid. The alternator is connected to the same terminal. From this terminal the complete car electrical system is supplied. So if the wire for the supply to the rest of the car is disconnected there should be no drain. Sometimes theres more than one feed to the car from the starter motor. If so by leaving one connected and others disconnected the drain can be narrowed down. The wires should be brown and fat. By touching a relay one can feel it work. By using a screwdriver with blade on relay case and earhole on handle one can also hear and feel the relay working. | ||
| David Gore Moderator Username: david_gore Post Number: 1806 Registered: 4-2003 |
Bob, Re the Porsche short circuit, one possible reason for the water becoming conductive could be the presence of a chemical build-up on or in the body shell over time from atmospheric contamination or the localities where the vehicle has been parked. For example; if the car is parked in the open near the sea, salt-laden air can leave salt deposits on the vehicle which can be dissolved by water forming an electrolyte capable of conducting sufficient current to cause heating of wiring/electrical components to initiate a fire if combustible materials are present. Another electrolyte source may have been a spilt drink that was not adequately cleaned up leaving a residue to be later dissolved to form a conductive liquid from the water leaking into the vehicle. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 731 Registered: 5-2015 |
Interesting about sugary drinks. The sugar gets hot and carbons which does conduct electricity quite well. Water is a good insolator. Its the impurities that conduct. So depending on what impurities and strength is how much resistance they have or conductivity. So sea salt and debris on the floor could make the damp act like a resistor and get hot sort of thing. Just the right conditions and bingo- fire. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 557 Registered: 5-2009 |
A buddy who has an auto repair shop loaned me a new tool he bought: supposed to be able to probe both sides of each fuse in place and read the current flow. It's made to find stray currents. Gonna try it next week while I am off. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 736 Registered: 5-2015 |
I had a clamp on self powered inductive ammeter. Which was very useful. But someone nicked it. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 569 Registered: 5-2009 |
Ok Battery drain Experts, I have an update: as it's a rainy Saturday I got out the new MAC troubleshooting tool and promptly found a small drain across Fuse 7 which is labeled "head flash". The drain is small 0.04 amp. Any ideas? I pulled the fuse and left it out and I will see if it drains the battery. I did also prove the interior lights, and boot lamp, are off when they should be. There is a festoon bulb which seems to be intended to light the fuse compartment, but I don't know how to turn it on. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1031 Registered: 5-2012 |
Hi Randy Have you not got a meter? The quickest way would be to undo the earth strap that connects to the battery negative terminal and connect a meter in series, switched to it's amps setting. Much quicker than waiting for the battery to drain. If you have isolated the leaking circuit then it's a major move forward. Just a case of metering it through using the circuit diagram as a reference. I am still looking for the drain on my car. I am doing it in a low key way as I can live with the fault by isolating the battery when the car is parked. Yesterday I removed all of the diodes in the fusebox, but alas, the drain is still there. I replaced them with new diodes. Interestingly only one of the "originals" had failed. This was open circuit i.e. would not conduct at all in either direction, rather than going short circuit. I was surprised all the others were ok, given their age. Next procedure will be to check the car's wiring from the battery through to the regulator. Geoff | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1032 Registered: 5-2012 |
Hi Randy Your reading of 0.04 amp is very low. Similar to the drain you would expect from the clock. Have you checked which circuit fuse 7 is for? Geoff | ||
| Randy Roberson Grand Master Username: wascator Post Number: 571 Registered: 5-2009 |
My main question is what does Fuse 7 protect? I can proceed from there. I will study my schematics. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 574 Registered: 5-2009 |
New information: I realized this afternoon that my meter has limited ability to measure Amperes so I got between the ground cable and the attachment point on the body and the reading was 175 mA. Obviously substantial. Everything but the clock OFF, doors closed, lamp out of the boot lighting fixture. Also, Fuse 7, which I identified as having some drain earlier, is pulled. | ||
| Jim Walters Experienced User Username: jim_walters Post Number: 49 Registered: 1-2014 |
Randy, those small bayonet lamps are 2 watts which is what your draw is at 12 volts. Have you checked the the red lights that are in the back edge of the door when open? Have you sat in the car at night or in a closed garage when it is absolutely pitch black and checked for a dim light anywhere? Glove box light? If it's not a lamp somewhere it has to be leaking voltage through a corroded connection somewhere. Check all relays that have live voltage to them with the key off. Unplug everything you can one at a time and check the meter reading every time. Remove the dash top and unplug the various relays and amplifiers like the low coolant amplifier and the interior light time delay module. I read you unplugged the alternator, have you unplugged the voltage regulator also? There IS an answer somewhere. SRE22493 NAC-05370 www.bristolmotors.com | ||
| Randy Roberson Grand Master Username: wascator Post Number: 576 Registered: 5-2009 |
It's in the dark now and I am going out to look one more time. I can hear a click like a relay, behind the instrument cluster, each time I connect the ground cable in the boot, I have been feeling all the relays to catch a warm one. Tomorrow I will pull each fuse in turn. I don't know what Fuse 7 does but everything seems to work even when it's pulled. I know the high beam indicator bulb is out. Thanks; you are right; there is a cause and I will find it. | ||
| Randy Roberson Grand Master Username: wascator Post Number: 578 Registered: 5-2009 |
Drain goes from 175mA to 35 mA when I remove the key from the ignition. I also hear that same relay-like click when the key comes out. Hummmn... | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 14 Registered: 7-2013 |
There is a solenoid inside the switchbox to prevent you removing the key when in gear, many of these get bent out of the way but the solenoid will still get power. On my shadow I had a slow leak to ground, I traced this to the drivers door interior light switch, the Bakelite had become conductive around the switch pins, I imagine this was caused by the switch opening the circuit for the relay for the levelling solenoid along with the lights, and or possibly moisture in the area, Best way to find it is to connect an ammeter in series with the battery with all fuses removed, if not zero then your problem is around the starter and alternator circuits which are not fused. Then replace one fuse at a time and check for any unexplained current flow. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1036 Registered: 5-2012 |
I'm still struggling to find the drain of 670 mA on my 74 SY1 (SRX18501). So far I have carried out the following checks and all have failed i.e. I still get the 670 mA drain on the battery: Checked for obvious causes (glove box light etc) Removed all the fuses and tested - 670 mA drain with all fuses removed. Replaced all fuse panel diodes Since I still get the drain even with all of the fuses removed, the drain has to be coming from the unfused alternator/regulator/starter area. On disconnecting the power feed from the starter motor I do get 0 mA. This rules out an internal leak in the starter motor, as only the starter motor was connected during this test. i.e. only the thick cable from the battery was connected and not the other wire that leads off up into the engine bay. I have checked the alternator by removing all 4 connectors - no joy - still 670 mA drain. My final test was to unplug the connectors on the regulator. I did this one wire at a time so as not to mix them up. Each check - 670 mA drain. I'm thinking maybe I should label up all the regulator wires and remove them all at the same time, to absolutely rule out the regulator. Next step, I guess, is to remove the top roll and check out the ammeter wires and connectors. Any suggestions are always appreciated. Geoff | ||
| Randy Roberson Grand Master Username: wascator Post Number: 593 Registered: 5-2009 |
As all the power comes from the pos cable disconnecting it will stop the drain. My drain goes down when I remove the key from the ignition with everything off: ? Did you try unplugging the voltage regulator? That's what mine was. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1037 Registered: 5-2012 |
Hi Randy As all the power comes from the pos cable disconnecting it will stop the drain. I agree, but if you disconnect the pos cable at the starter motor you are checking whether there is a leak on the actual cable. Connecting the cable back to the starter motor, but not the other cable that runs into the engine compartment, checks the starter motor for leaks. Earlier I disconnected all wires to the regulator and again found I was still leaking 670 mA. This is a really strange fault. It must be somewhere in the ammeter circuit. As an aside, whilst I had the regulator off my car I took a few photos, which I'd forgotten to do when I replaced the original faulty regulator a year or so ago. The unit is a Durite 0-830-12. I can recommend it as a replacement for series 1 cars - mine is a 74 SY1 (SRX18501). A quick google search gave the lowest price as GBP 26.39. https://www.autoelectrical.parts/product/0-830-12-regulator-c-a-v-12-volt-electronic-qty-1/  I should add this is a new part. The one in the photo has lost the as new shine, after a year+ in the engine bay. Geoff | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1038 Registered: 5-2012 |
https://www.autoelectrical.parts/product/0-830-12-regulator-c-a-v-12-volt-electronic-qty-1/ |
