Auto Electrician advise wanted

Hi Chaz,

Ashdown are the real thing !! Had two for years with no trouble and there are thousands being used.
Used to energise it with oil pressure on me old ford but can't on the Nissy.
I got a Redark for my Nissy and think i wasted the money.

Well, I am an Auto Electrician. There is no problem using a Cont. Duty Solenoid to charge a second Battery. However, Make sure that You use a Circuit Breaker to the Second battery if Your using smaller wire to the Second battery. Otherwise too much current may be drawn from the second battery while cranking.. If you use the Same wire or larger as the wire used to the starter originally, You can omit the circuit breaker. I use a good quality Welding Cable. The advantage of this is that you can jump start from the Second Battery if the Main battery goes flat by bridging the Solenoid or switching it.

There is no problem taking a 12volt source from the Wiper Motor circuit to switch the solenoid. You do not need a delay if charging 2X12 volt batteries..
There's no problem if you use different batteries as long as they are both 12 volt. Think about it. If one battery is down and ther other fully charged, They can only equalise to 12 volts or whatever the Fully charged battery voltage is floating at..

Further Note. Automatic switching devices made for this purpose really only do exactly the same thing except for some enhancements. They work by charging the main battery first, then when it's fully charged, it switches in the Aux Battery Solenoid or Relay to charge the Aux Battery.
They work by sensing the Main battery Voltage. When this voltage reaches Approx 13.8 volts, That's when they switch in the Second Battery. You pay a high premium for this system.

I have fitted over a hundred Aux Batteries to 4WD using just a Continous Duty Solenoid and have never had any problems whatsoever, but, I have had customers come in who have had trouble with their Auto Switching Systems.

Hope This Helps.
Regards

G'day Damian007,

I have to agree on the above as I have been:
Using heavy wire simular to welding wire from starting battery to solinoid and from solinoid to Aux battery, a LM430F for starting and a DC55C deep cycle as auxillary battery in a ford ute and the same in a ford wagon since 1998 with no charging problems. The Aux battery runs a fridge and a 100 watt transmitter with no problems. It will now go into my Patrol till it dies and It maybe replaced with another latter.

My main Question is:
Is the Auxillary battery used when cranking the motor if the power wire to solinoid is wired to wiper motor?.

Thank you for your help. P&J.

G'Day.
You might find that the power to the Wiper Motor may be cut while cranking..An easy way to find out is use a test light to find the power while the ignition is on..Crank the Vehicle and see if the test light goes out.
Most vehicles cut power to the accessories while cranking so full power is applied to the starter motor.

The system I usually wire up uses a Continuous Duty Solenoid and Heavy Welding Cable..
I wire up the Solenoid to a sutable power source while the ignition is on..This can be from the Wiper Motor or some other source.
I put a push button switch on the dash with power from the Aux battery. This supplies power to the solenoid if the main battery goes flat. You can then use the Aux Battery to start the vehicle if the main battery goes flat. This way you don't have to worry about jumper leads etc.

Hope that helps..

G'day,
Fully understand the testing when cranking over, will try with test light or multi-meter and see how goes.
Ok on the momentry swith on dash as well, know what you mean.
Thanks for your help. P&J

If the relay you are using is not voltage sensed or have a delay, using the wiper motor will cause both batteries to equalise before/or as you start the motor.

The Arrid smart solinoid has a 1 min delay after it's had power put to it to prevent these problems, I'm not sure if your's does...

Probally the best thing to do would be to take the cover off from under the steering columb and get your multimeter onto the ignition, have a look around for 12v that's only there while the engine is running. There should be something on there for this.

the info regarding the 12v pickup was given to me by an auto electrician who was trying to sell me on the idea of a solenoid system.
Explained like you have I am glad I went with the system I have now that was suggested by another auto that is voltage sensitive.
Will

Hi to all above,

Thanks for your replies and suggestions. I personally do not like the idea of using the wiper motor wires as solinoid would be switching in and out all time.
Thanks for your input Donk (techie) thats the answer I wanted, sounds fair enough to me and makes sence.
Just hope it won't effect the Computer on vehicle.

Thanks All P&J

Need ur email Techie please. Have heard that ign light glows faintly in dash of night time doing it this way. Have you noticed it ?

Thanks P@J

Don't use the Alternator Light Circuit. Depending on type of Alternator, You may Damage the regulator. Firstly from Back EMF. It's not designed to run anything more than a 2-5 watt lightbulb. Secondly, from current draw.Some Alternators may handle it better than others but you take a big risk. The relay may also have trouble dropping out.

The alternator light will glow faintly in some instances because of the return to ground through the relay. The Alternator Light Circuit is not only there for a warning indicator but it also Excites the Alternator by supplying it with a small amount of current to start the charging process after you start the vehicle.

Thanks Damian007 for your follow-up. I think you are correct in what you have said. This was ok to use on the older cars of the 60-70's.
It worked ok on my old HJ ute, but a bit sus nowdays.

As we in the programming world would say:
A complex system, with it's inherent problems, is invariably found to have evolved from a simple system that works fine.

I find most complicated devicescan be replaced by simple ones that do much thesame job,butwithout all the bells and whistles.
Regards
Techie

As we in the programming world would say:
A complex system, with it's inherent problems, is invariably found to have evolved from a simple system that worked just fine.

I find most complicated devices can be replaced by simple ones that do much the same job, but without all the bells and whistles.
Regards
Techie