revtothelimit - motorbike forum

What is this meter telling me. Is that 3.7 milliamps? I need to go hunting for a Parasitic drain tomorrow but not 100% au fait in using the meter.

It all depends on the range you've set your multimeter to, I think. In the illustration above the switch is set to mA - milli-amps.

mangocrazy wrote: Sat Jan 18, 2025 10:44 pm It all depends on the range you've set your multimeter to, I think. In the illustration above the switch is set to mA - milli-amps.

Wiki says up to 50 milli is OK as you have radio clock, alarm and the likes taking a bit power. I had a slight loom fire in the camperbus what i thought i sorted but my start battery died quite quick this winter. The fire seemed to be in the window wiper motor wiring all at the fuse box what i bypassed but as i just put a new battery in i want to double check that that setting is just a low 3.7

I'm not sure what an acceptable level of parasitic drain would be. The drain in the picture above wouid be 3.71 milli-amps, which is a lot lower than what Wiki says. But to be honest I wouldn't know what's a 'good' amount of drain or a 'bad' amount. You need to ask someone like Mr D...

They say between 20 and 50 is OK. I dont have a radio but now i am thinking about it i do have a soundbar on the dash running through an Inverter. I must check i never left that on and the soundbar on standby. I may have bought a battery for nothing

It depends on how long you're leaving the vehicle for between running it, if it starts when you want it to, it's nothing to worry about.

Shouldn't the wire be plugged into the "mA" socket in that pic? So the pic shows 3.71A not 3.71mA.

You can look for parasitic drain in the fusebox BTW, standard automotive fuses have a set of terminals on the back too put there for precisely this reason. I haven't actually watched this vid, but the pic shows the idea. Maybe the content is accurate too!

Bear in the mind that the (hopefully!) tiny reading you get across the fuse isn't the loss in the system, it's just the drop across that fuse. You'll be reading volts not amps too. You then need to consult a table to see what that reading corresponds to as an overall draw. For the most part you're just looking for an 'on/off' level of assessment though, so any reading other than zero shows you've got a 'leak'.

It's not really possible to say if 3.7A is a lot or not BTW, it depends entirely on the circuit. I wouldn't have thought an electric window circuit is designed to draw 3.7a continuously, so the fact you had a fire isn't surprising. What constitutes "too much" current is a factor of time as well. 3.7A for 10s is quite different to 3.7A for 2 hours of course!

Mr. Dazzle wrote: Sun Jan 19, 2025 11:20 am Shouldn't the wire be plugged into the "mA" socket in that pic? So the pic shows 3.71A not 3.71mA.

You can look for parasitic drain in the fusebox BTW, standard automotive fuses have a set of terminals on the back too put there for precisely this reason. I haven't actually watched this vid, but the pic shows the idea. Maybe the content is accurate too!

Bear in the mind that the (hopefully!) tiny reading you get across the fuse isn't the loss in the system, it's just the drop across that fuse. You'll be reading volts not amps too. You then need to consult a table to see what that reading corresponds to as an overall draw. For the most part you're just looking for an 'on/off' level of assessment though, so any reading other than zero shows you've got a 'leak'.

It's not really possible to say if 3.7A is a lot or not BTW, it depends entirely on the circuit. I wouldn't have thought an electric window circuit is designed to draw 3.7a continuously, so the fact you had a fire isn't surprising. What constitutes "too much" current is a factor of time as well. 3.7A for 10s is quite different to 3.7A for 2 hours of course!

Ah that looks a better idea. I never made it down to my bus today and a also know i dont have them fuses but i may just go order a mixed bag and swap them over as i test them. Saying that them in the video look like the little micro fuses. Hopefully then come like that for the larger standard version.

Le_Fromage_Grande wrote: Sun Jan 19, 2025 9:30 am It depends on how long you're leaving the vehicle for between running it, if it starts when you want it to, it's nothing to worry about.

I was down to fit a new battery and alternator and that weas the first in five weeks. Solar should have been topping up the battery but the weather has been shit but i should have got some charge. This is what is making me think i may have left the invertor on and the soundbar will be on standby.

Felix wrote: Sun Jan 19, 2025 8:43 pm Saying that them in the video look like the little micro fuses. Hopefully then come like that for the larger standard version.

Yeah they should do, the reason for having the exposed terminals on the back is so you can measure the voltage drop across them in situ. It's the "proper" way to find a leak/the load in a circuit, way nicer than pulling them out when the vehicle is on and trying to see if your meter changes.

See how the terminals go right up to the "top" of the fuse, while you have the zig zaggy melty bit in the middle. I'm sure there's a proper name for it.

Doesn't mean 100% of the ones you find are like this though, that'd be too easy

Mr. Dazzle wrote: Sun Jan 19, 2025 9:54 pm

Felix wrote: Sun Jan 19, 2025 8:43 pm Saying that them in the video look like the little micro fuses. Hopefully then come like that for the larger standard version.

Yeah they should do, the reason for having the exposed terminals on the back is so you can measure the voltage drop across them in situ. It's the "proper" way to find a leak/the load in a circuit, way nicer than pulling them out when the vehicle is on and trying to see if your meter changes.

See how the terminals go right up to the "top" of the fuse, while you have the zig zaggy melty bit in the middle. I'm sure there's a proper name for it.

Doesn't mean 100% of the ones you find are like this though, that'd be too easy

I was looking back in a picture when i had the dash out exposing the box. I do have them fuses and will be going down to the bus tomorrow. I know i have an issue with the tail lights as they have a low voltage going to them when the ignition is on but that should not be my drain as when the ignition is off it kills this low voltage. My problem is my bus was just a chassis with a cab and sold to a company called Truck Smith what i think changed to Coach Smith. Then make the fiberglass shell to put on the chassis to make the bus. Do you think they used the same colour wires as LDV from the cab to the back of the bus? Did they hell so that is using the original wiring diagram out the window

Well thankfully i never had a Drain. That got me thinking why the split charge never switched over to the start battery when the leisure was full. Started to check all the wires from the solar charger back to the battery. The link wire from battery to split charger had a bolt in the fuse work loose. The new battery jumped from 12.5v to 13.6v when running on the solar so all is good again (Y)