I would like to fit a volt/clock on my pv544 1963 it has a b20 engine fitted with a alternator , anyone any advice on the wiring, ( is it better with an volt/clock. or ammeter.for there seems to be different opinions on this )

PC

If you want to try a voltmeter - search the web.

You can get a combo clock, inside temp, outside temp and voltmeter - or - voltmeter, 12 volt outlet, plus 2 USB ports for 20 bucks or so!

S&S;

...it's not as simple as "better or worse"...this is a matter of philosophical discussion and personal preference, and I do have mine...because the two instrument do indicate somewhat different things happening in the Elec Sys ...but I will present this as objectively as I can, so you can decide for yourself.

Ampmeter indicates Charge/Discharge Battery current (which is important to me and I want to know it more than Voltage, because it is the electrical reserve of the vehicle, and 100% to 0% charge condition happens within 0.8 tenths of a Volt, so a Voltmeter doesn't display this very well). An minor disadvantage is that typical Ampmeter wiring requires heavy wiring to instrument because large currents pass through instrument. Correct wiring should be per "H" diagram (See Reference)

Voltmeter indicates System Voltage (which is not not less important than Current, but less informative as Sys V gets pulled up or down as a function of state of charge of Battery and Loads. Also, there are other indicators of system voltage - Headlight brightness, Wiper/Blinker speed etc.). A minor advantage is that Voltmeter can be wired with small gauge wiring as only a small sensing current is used by indicator. Voltmeter can be connected just about anywhere in system because it draws so little current, but close to Battery is recommended.

(Reference: http://www.sw-em.com/elecramb.htm )

Bottom line is that a gauge is much better than an "Idiot Light" only, because it give us more info on the health of car's Elec sys...have fun deciding!

Cheers

Ron, you are a gentleman and a scholar! It would be hard to find anyone these days under 70 who has not been brainwashed and understands why an ammeter provides more useful information. After the 1950s they started using voltmeters because it was a lot cheaper. You could actually avoid running heavy wires to the dash using a shunt and milliammeter, but that's also expensive. I've run the wires and installed ammeters on most of my vehicles. Even the smallest, cheapest ammeter will tell you if the alternator is charging or not.

A voltmeter has to be very precise and accurate and you need to memorize the exact voltages that would indicate what's happening. Voltmeters in cars don't read in 1/10ths of volts and are of dubious accuracy.
--
1992 745, >500k km

John;

Agreed, if engine is running, and Ampmeter is in the negative, there's cause for concern...with a Voltmeter (even expanded scale type), it will never be as simple as that...

Most design changes happen for a reason...in the case of Ampmeters being almost universally replaced in vehicles by Voltmeters, you and I are in agreement that it was undoubtedly for $$$ reasons...it is without a doubt cheaper to include a Voltmeter, than an Ampmeter...what might bother some is that then they give some pseudo BS technical explanation trying to justify technically why they made the change...and I'm not 70!

Cheers

You make a very good point I hope to illustrate with one scenario. A bit off topic, because our cars are all 2 series Volvos, but the basics of battery charging still apply.

I had a situation for some time (12 years ago) in my 300K+ commuter car where I felt the alternator was not handling the load of driving with wipers, heater, defroster, and headlights along with replenishing the cranking drain at a reasonable rate.

The voltmeters (2) indicated charging rather than discharge, but I could not be sure the battery wasn't sulfated to the point where the charging current never rose to load the alternator. Or were the three-pulley belts glazed and slipping when the load was there? An ammeter will tell you this at a glance (although the picture below wasn't that particular glance).

Of course, the 240 is especially problematic for an ammeter unless the wiring is modified to bypass the starter. A lot of 8-gauge wire later and I had the information I was after (the belt was silently slipping*) but I wished I had a zero center milliammeter to install with a shunt, because running all that stiff wiring into the cabin to a cheap tin ammeter is a prescription for fire unless every detail is anticipated and cared for.



When I took it all out, the firewall grommet did not get plugged, and that 3/4" hole was enough to allow several mice to gain birthright citizenship under the carpet.



I still use voltmeters, one digital, and have learned to follow the temp comp curve of Bosch's EL series regulator with them, but a zero-center remote shunt-sensed ammeter with the decor to match a PV would seem to be the right thing to have in a PV.

* The slipping belt under load without squealing: finally proved this by connecting a speaker to the "W" terminal (used for tachometer output on Diesels) but the ammeter was enough to alert the marginal charging current.
--
Art Benstein near Baltimore

Don't let people drive you crazy when it is within walking distance.

Thanks RON , went on to your Ramblings, OK ! now.
S&S

You have reached a non working page at the Swedish Embassy Volvo Website Hit the back button to return to the previous page.
Ron, there must be a SHORT in the wiring because the above was the answer to your ref.
(Which goes to prove water and electricity don't match )

S&S

S&S

I just tried it, copying link and pasting it into address bar of browser...and it worked fine, taking me to the Electrical Ramblings tech article on SwEm site...I suggest you try again:

http://www.sw-em.com/elecramb.htm

Cheers

THANKS RON (YOU'RE OH! SO CLEVER ) you have just explained WHY I asked the question, but now I have to make a decision and that's why I asked , you have just thrown (what you lot over the water call ) a curve ball. The explanation is very
precise so thank you very much for that, all the best and a MERRY CHRISTMAS. He! He!
S&S