Date: Fri, 6 Jan 2017 16:42:57 -0800
Reply-To: Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject: Re: Dang driver lowbeam and front driver turnsignal
In-Reply-To: <CAMOH8LJ6KRg8uS12ngd=UhyR1+sjNdA6hCNg5YEZ95MeX+33Yg@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
Good ole Harbor Freight! Some for $4.99, which one do you like? http://www.harborfreight.com/catalogsearch/result?q=multimeter
Stuart
From: dbeierl@gmail.com [mailto:dbeierl@gmail.com] On Behalf Of David Beierl
Sent: Friday, January 06, 2017 4:24 PM
To: Stuart MacMillan
Cc: vanagonlist a
Subject: Re: Dang driver lowbeam and front driver turnsignal
Stuart, Harbor Freight has $6 (sometimes free) meters that are perfectly adequate for almost all van electrical stuff (better than the RS folding one in some ways) and easier to find/use for one fifth the price.
What you need in a van digital multimeter are:
Banana jacks so you can use different test leads or adapters.
Power switch that is not a pushbutton that could get turned on in your toolbox.
Manual ranges -- auto-ranging is nice, but if you can't turn it off it can drive you nuts in some circumstances. Much better to not have it than have one that can't be turned off (most auto-ranging *can* be turned off).
Accuracy -- the cheapest digital meter is more accurate than all but extremely expensive analog meters, and accuracy is specified in terms of the reading rather than the meter full scale. It will be good enough, sight unseen, until you are advanced enough to work out the ramifications yourself.
High impedance -- the standard input impedance for electronic voltmeters is ten megohms, which is excellent. The lowest I've seen on a digital multimeter is one megohm, which is still plenty for any normal van purposes. Cheap analog meters have an impedance of 2,000 ohms for every volt on the scale, so a ten-volt scale would have 20,000 ohms. Sounds like a lot, but it will drag your oxygen sensor practically to ground. Huge win for digital in this case.
DC Volts -- 20, 2, 200 mV (fancier meters with more "counts" may read up to 3999 or 4999 on a range instead of 1999).
DC Amps -- Ten or twenty amps and a milliamp range of some sort. Note that the high-amp range on cheap meters is usually un-fused, so if you try to read volts with the leads connected for amps you will smoke the meter shunt and maybe melt the meter case. OTOH the fuses on my fancy Fluke meter cost more (each) than the entire HF meter...
Ohms -- 200 ohms to at least two megohms ranges. You won't actually use these often, as you'll mostly be concerned with resistances that are too small to measure accurately (or at all) by this technique. Instead you'll be using the 200 mV scale on live circuits to get voltage drops directly, which is the number that matters in any case. In effect you are turning the van and meter together into an extremely fancy ohmmeter that can measure milliohms or even microohms.
Diode Test -- Like ohms, but shows voltage across a semiconductor that's conducting. Modern digital ohmmeters use too low a voltage to turn on a semiconductor junction, so they have a special function that will. It's nice if this function has enough voltage to turn on blue/white LEDs -- some do, some don't. Pretty much all of them will work with red/yellow/green LEDs, and all will work with germanium or silicon diodes.
Your $6/free HF meter does all this. For an extra buck or two you can get one with a light.
Things that are nice:
Continuity buzzer -- nice, but can bite you since they usually beep somewhere between 50 and 150 ohms. That's ok if you're looking at a circuit with an incandescent light installed in it, but not for wires connected together, switches and so forth. But if you ever get a chance at an old Hickok meter with ?Vari-Trak? (audio beeper that changes pitch with the meter reading) grab it. It's a huge pity they went out of business and nobody has picked up this idea.
Bar graph display -- digital meters typically take 2-4 readings per second, and average the reading over the measuring period which will be roughly one-third of the cycle time. For rapidly changing readings (like the oxygen sensor on the van) this can lead to readings that appear random. Slightly fancier meters often have a secondary bar graph display that isn't precise but responds much more quickly than the main display.
Illumination -- can be very handy. If I had to pick between continuity buzzer and light I'd probably pick the light.
Display hold -- lets you make a measurement and capture the reading to look at in better conditions.
Min/Max -- captures the highest and lowest values of a reading. Handy for example when measuring voltage drop during cranking.
Frequency/duty cycle -- good for PWM (pulse width modulated) signals like the 2.1l Idle Control Unit output, LED dimmers and such.
DC+AC -- digital meters on DC ranges typically ignore AC. This function gives a separate reading for any AC component of a DC signal, like ripple and hash on the alternator output. Probably only on quite fancy meters.
Type K thermocouple input for temperature. Even nicer if you can switch the reading for F or C.
Auto-timeout on light and meter power -- can save your battery. Can also be a nuisance, so even nicer if you can shut if off.
Yours,
David
On Sun, Jan 1, 2017 at 11:19 PM, Stuart MacMillan <stuartmacm@gmail.com> wrote:
No, you are not being obnoxious, basic electrical troubleshooting requires one. At least get of one these, I give them away to my friends and family: https://www.radioshack.com/products/radioshack-22-range-pocket-digital-multimeter I now have a Fluke meter, but I still have the Radio Shack pocket VM I bought at least 30 years ago in my Vanagon on-board toolkit.
Stuart
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dennis Haynes
Sent: Sunday, January 01, 2017 7:43 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Dang driver lowbeam and front driver turnsignal
I’ll ask for forgiveness in advance for sounding obnoxious. Besides changing parts did you consider using a meter? Each headlight high and low bam does have its own fuse, yes 4 fuses for the lights. They are after the switches in the headlight circuit. The turn signal sounds like a bad ground, probably at the socket itself. The 4 way flasher is not an independent circuit. The flasher will not flash unless it sees enough current being drawn for two bulbs. High resistance in the working or a bad bulb will prevent the flasher from working. This acts as an indicator of a turn signal being out. The 4 ways connect 4 lamps so if one or two were out it will still flash. Headlight grounds are also a common problem. There are grounding clusters above the fuse box. It is common for the quick slide connecters to both corrode and also break just from heat and age. As the headlights are higher current items new ground connections near the headlamps are a good idea.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of C B
Sent: Sunday, January 1, 2017 7:48 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Dang driver lowbeam and front driver turnsignal
My driver lowbeam won't work at all.
What didn't help:
Swapped bulbs.
Replaced turnsignal ring & stalk.
Replaced dash headlight switch.
Traced wires and pulled apart the fuse block and driver's side wiring stars connectors. (Should I try the passenger side one?)
In addition, the driver front turnsignal stays on and won't flash whether just parking lamps, or either headlight combination is on.
BUT the driver front flasher works in emergency 4-way flasher mode regardless of parking light/headlight configuration.
I know the 4-way flasher is its own circuit, so where in the parking/headlight circuits are likely culprits?
Other than that, Cunegonde finally home and ready for visual restoration.
It's been a long several years since the engine debacle.
CUNEGONDE 1985.5 2,1l WBX 4sp Westfalia
