zed Posted August 11, 2016 Report Share Posted August 11, 2016 Greetings gentlemen, Can someone possibly explain this: I've got a Ford pick-up, slowly losing battery charge; ammeter shows the draw with ignition OFF is about 180 milliamps. It has spotlights, wired through a 30 amp relay (Hella). With ignition OFF, I can hear the relay 'clicking' when I connect the battery terminals - even though the headlights and spotlights are OFF. The spotlights are spliced/triggered by the "High Beam" headlight wire. The spotlights and headlights work fine. But, just in case, I changed the 'signal' and 'earth' connectors (think it is '85' and '86') on the relay pins around. Now the 'click' is gone, and the 'off' current draw is down to about 30 milliamps... does this make sense? These spotlights were installed by an auto-electrical workshop. Any opinions would be appreciated, thanks 1 Quote Link to comment
DanielC Posted August 11, 2016 Report Share Posted August 11, 2016 Any coil, when switched off has a inductive voltage spike, that is how the ignition coil works. Relay coils do this too. If a relay is hooked up to sensitive electronics, like a engine control computer, this inductive spike can damage the computer. If you wire a diode across the relay coil, in reverse polarity, the high voltage spike is absorbed by the diode. This is also why many times the coil of a relay is wired always hot, and the controlling computer switches the ground side of the relay coil. Quote Link to comment
banzai510(hainz) Posted August 11, 2016 Report Share Posted August 11, 2016 what year is this Ford? Most Jap made vehicles use a switchable ground. Ford I dont know maybe its a switchable power. pin 85/86 is getting power or a ground to comeplet the circut thru the tiny coil thus most like its the draw you say it is. If you disconnect one side 85/86 then the Ford is fine I assume this is the proplem. I would ck the wire going to the relay. 85 or 86 and see which has power when you hook up the battery. relay is only going to click if wsoemthing is feeding it. this is how my 510 relay is wired. I use the high beam light as its a 2 prong light. I jammed one wire to each side.85/86 On 510s both sides are wired to the 12volts via the fusebox. then when I hit the high beam one side goes to ground. thuds clicking the relay to my Hella 500s lamps on my bumber Daneil might be right as there might be a diode in there in parallell with the coil. but that would not cause the draw I would thinka s a draw would need a pos or neg that completes the circut I always use a test light when cking for drains on older cars. in series with the battery Quote Link to comment
zed Posted August 11, 2016 Author Report Share Posted August 11, 2016 Thankyou Hainz and Daniel, it makes sense Quote Link to comment
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