Club 80-90 Forums

I require some help please.... For several weeks now I have had a problem with my main battery, or so I thought. When ever I did any checking on electrical items, ie Lights, trailer connector, radiator fan Etc I found the battery was going flat very quickly. But I could leave the camper for weeks and it would start OK. This got me thinking, was it battery or something else causing problem. So decided to check.
Firstly I removed the Pos cable from the battery to check with ammeter. Ammeter between battery and cable. With ignition off no reading, Ignition on 45 amps, this I think is to high. may even be higher as the meter only reads 45 amp.
Separate the three wires on terminal clamp and check with ammeter..... Main cable to starter no reading,..Wire to leisure battery no reading....Wire to main vehicle loom 15 amp. All appears OK. Double check..Leisure battery wire and main loom wire together... 15 amp....Main cable to starter main loom wire together 45 amp..... This I do not understand. One cable with no reading plus one wire with 15 amp reading should not equal 45 amp. Or am I missing something.
All suggestions, ideas and recommendations welcome.

That would imply that there is something connected to the starter cable through a relay that is switched by the ignition.

Sorry cant see that. Why can two cables with different readings when joined together give a different reading of the sum of the two. I know I am a bit slow, call it an age thing.

Well if it was as I suggested, when just the starter cable is connected, the relay wouldn't be energised and so no current would be drawn. When the ignition is on but starter cable disconnected, then the relay would be energised but the main feed disconnected, so no current drawn. With both starter cable connected and ignition on, then relay would be energised and feed live so current would flow.
So it would be connected to the non-battery end of the starter cable, eg to the terminal on the starter motor, via a relay which is energised by the ignition circuit.

Not saying this is what you have, but it is an example of something which would give the results you are seeing.

Thanks for reply. I think I have not explained my self very well. When I said that I connected starter cable to main loom and tested them, I had not connected direct to battery. Only via ammeter.... Ah now I see what you mean. .. I AM connected to battery. Via ammeter... I did say i was a bit slow .
So I now have to find what is connected to starter cable.. hay . ho

Ignition on 45 amps, this I think is to high. may even be higher as the meter only reads 45 amp.

That's a lot of amps to be doing "nothing". Is the leisure battery completely flat and the starter is trying to charge it? Try disconnecting the leisure battery and see if the 45 amp draw disappears.

I would disconnect the alternator and test again

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carb heater element ?
Choke element
Three relays for the LPG
Coil

That lot shouldn't add up to 45 amps .

I would be unplugging the carb heater and the choke in the engine bay and pulling the fuse to the LPG system and see if any different reading

Don't you have electric power steering ? Pull the fuse on that too and see if any readings change

Steve...Checked power steering. Not yet checked the others. What I cant understand is this has happened over the the last couple of Months.. Will check others later.

MGP..Have done so.

BOXY....Problem only happens with ignition switched on and engine not running. Leisure battery is only in use (connected) with the engine running at above tick over. Thanks for input.

Do you know how many amps are supposed to be drawn anyway with the ignition on?
Perhaps this value is correct and the battery is just on its way out?

What sort of meter are you using to measure the current? 45 Amps is beyond the draw you would get with everything switched on. Are you sure you've not misread the scale? If something is really pulling 45 amps and not doing any work I'd expect cables to be getting hot and insulation to be melting. I think you'd need a 10mm cable to carry that sort of current for any length of time.

Yep, re reading this, the basic over the counter multimeters cannot handle that sort of power , most are 10amps max
You sure it's not 4.5amps you are reading ?

What are you using to connect the leads of your meter to cables & battery. A bad connection on either end could result in a false reading due to current drawn through a bad connection.