Circuit testers/meters.

[AW8]

Radio CD tape not giving any sound on X5. (12/01 build E53 with 16:9 Comm's & without DSP) . Have checked fuses including the one on back of the radio module. Overnight failure as opposed to gradual deterioration to various speakers. I may post elsewhere re these woes but essentially I need to rule out wiring problems before sourcing another module if indeed that is what is required.

Next step is to check wiring is all good but don't have a circuit tester.

Basic tester to confirm power feed and cable integrity is all that required to check the pins connectors to the plug that goes into rear of the module & was therefore thinking of buying a basic but functional circuit tester unit like this

I am also mindful that X5 can often suffer current drain so was thinking of buying this which would check circuits but also indicate drains, however, aware it only has a few led's (3,6,9,12v), .and doesn't give accurate voltage output.

I am assuming that to be able to check both wiring/feed integrity via small pin connections & to also be able to measure any drain I would need something with a small pointed probe & an accurate voltage display. With this in mind it seems I would need something like this

Essentially at this stage priority is to check all feeds to radio module are good, however, interested in knowing what folk use or advise for in terms of both as circuit testers &/or meters.


Thoughts appreciated

[X5Sport]

The linky to the second device just brings up a blank page on my iPad.......

However. I use a full multimeter that I got from Maplin to replave my good old Avo8 MkV that got run over - don't ask!

It's a professional one, at least as professional as Maplin sell but without getting into the silly money Fluke full multimeter territory, called a UNI-T UT70D. Not cheap, but covers up to high voltages which I need to be able to do. It also auto-ranges so no thinking about what setting to use.

http://www.maplin.co.uk/ut-70d-true-rms ... eter-34801

With regard to checking for current leakages you need to be much more careful as there are two ways of doing this. One is to use a device called a 'Current Clamp', which is basically a coil that goes around the cable and measures the magnetic field thst any current flowing through a wire will generate and then displaying that info in the right Amp range. Great for large cables and large currents such as starting current. Not terribly convenient in a bundle of wires. The second option is where you place the metering device 'in circuit' so the current and voltage flows through it and measurements are possible. BUT this is where you need to think about the maximum current you are trying to measure against what might be flowing. My meter can handle 10A through a special port. Any higher and a fuse blows. If your device is unfused nd you overload it then there are the usual risks of a burning smell, spatks, hot fingers and a trip to A&E!!

For DC current then you need summat like this one. Manual ranging only but cheap.

http://www.maplin.co.uk/ut50a-manual-ra ... eter-46390

If you are using the in circuit mode to see what the leakage current is then that's fine as long as the car does not draw more than 10A when 'awake' but nothing switched on. I used it to find a high current draw in the boot lock and left it in circuit until the car went to 'sleep' at which point you can see the idle current draw. If you need higher current then some manufacturers supply a current bridge which can cope with perhaps 50A so the meter doesn't have to.

Circuit testers are absolutely fine as a Go/No Go device but that's it. I have a very old on which is a 12V Festoon bulb and two bits of wire one with a croc clip and the other a sharp point for getting into the back of connectors etc.

Does that help?

[AW8]

Yes that helps.

Draper 57860 was on the 2nd link more info also on the following link http://www.draperproducts.co.uk/57680/D ... STEMS.html

Dont know why the 2nd link to my 1st post not viewable on ipad as I can see it on the macbook pro I am using.

Looking at multi meter cost & operating complexity I have just one question. Do you think the basic circuit tester in 1st link would be adequate to check for integrity of inputs to the pins to plug that connects to the radio module ?

Thanks - I know you have some electronics background so your comments are valued here.

[X5Sport]

Oops- it's the 3rd one that's blank

And yes, a basic one will tell you if you have volts on the pins that are supposed to. A basic Ohm Meter will also allow you to check continuity on things like the ground pins in case you've lost an earth, or do end to end checks when looking for broken conductors. Always a good idea to connect the meter to the local ground in the connector if looking for 12V switched power and if it's missing then try another chassis ground. This can sometimes find a bad earth.

I do have an electronics background as you surmise. Mainly in radiocommunications systems. I hate car electrics as they're far too complex now, and with optical buses now included that just adds another dimension to cover off. As long as I can get a circuit diagram I'm happy though (assuming you can then find the actual wires of course!!).

A tip for checking long nd to end runs is to disconnect both ends, find a conductor that does go end to end and is not used for anything else or branched and make a wire link to bridge that known good wire to the one you're checking so you only eed to be at one end if you're working on your own. If there's two of you then the second person can move the loopback wire to the next colour/pin you want to check. You may need to get some identical but opposite male or female pins to put on the ends of the loopback link - saves faffing about trying to get the loopback to stay in place..

[AW8]

3rd link to OP now edited & working.

The more I read the more a trip to the indy seems appealing.......thanks for sharing -will digest albeit a little info in wrong hands can end in disappointment.

[Rusty]

[quote=""AW8""]3rd link to OP now edited & working.

The more I read the more a trip to the indy seems appealing.......thanks for sharing -will digest albeit a little info in wrong hands can end in disappointment.[/quote]

Don't be put off, it's really not that difficult, and as long as you buy a reasonable DMM (digital multi meter) you will be able to sort many things out.
The biggest problem with clamp meters is that they are rarely accurate on low current applications and so a through meter test would be much better as previously mentioned by the very knowledgeable Mr sport.
I use a Fluke meter myself as I have one, but some of the Maplins ones are perfectly adequate.

'Edit : The second one recommended seems very reasonable and with a good range too.'

Just be a bit sensible if disconnecting cables so as they don't ground out, and all should be fine.


Sent from my iPod device using Tapatalk

[X5Sport]

A Fluke - lucky you!! And yes you are quite correct about current clamps. The ones for small current measurements are serious money!! Fine if your test equipment budget was like mine when I worked for the Government - several £M a year - but not for the mere mortals like us.

If you're mind works in a methodical way and you have the patience then tracing wiring faults is a straightforward process, it just takes time and patience. One of my jobs used to be checking 1800 pair telephone cables - now that's a job for the patient!!

When SWMBO's E46 went down it was caused by the indy doing something silly - they'd given the battery job to their junior trainee - but we don't know exactly what. They had to find and fix the faults without access to the full BMW testing hardware

Part of the issue with BMW's, and almost all modern cars is being sure that what you see is what you really should be seeing. Power is always simple, as is continuity as long as you know that what you are checking isn't branched anywhere. The fun bit comes when you have to take signalling into the mix - at which point your test equipment budget goes out the window.