I checked my amperemeter today but it don't move left or right. Installed a new generator (from a Mercedes 80's) and installed the control light. This light works very fine therefore the generator works too. I take an instrument and take the volts and amperes to the battery..all is correct but the amperemeter don't work. Could anybody describe who is the resistor on the amperemeter or works this without a resistor? Volker
Ammeter My guess is Evan will make more sense than I but here goes : The ammerter must have the hot wire from the battery going through it to work . There's no resistor nor shunt .
If I remember the 46 ammeter wire just passed through a loop on the back of the gauge rather than hooking to two terminals. Either way this crude check will tell if the gauge works. Hook the wire on one side of the gauge to the positive battery post, or any hot wire terminal, and then arc the other to a ground. Don't hold, just arc. The gauge needle should jump like crazy to either maximum charge or discharge reading. If it doesn't move it's definitely not working.
Ammeter wiring It depends where in the circuit the meter is. If it is on the generator output and supplies all the lights etc as well as the battery, you should see a positive current all the time that changes when you say, turn the headlights on and off. The last car I had with an ammeter (1959 Jaguar) had it on the battery charge wire, so if the battery is charged up, you would not see any noticiable current. I looked inside one once. All that was there was a single loop of heavy gauge wire with a small magnetic needle next to it. The needle responds to the magnetic field set up by the current in the loop.
Ammeter. You might want to check out the output of the MB generator.....most old truck ammeters aren't calibrated to handle over 30 amps. I know they will pose a potential fire problem if inadvertantly tied into a high amp system. As long as your light is indicating a charge you should be okay on that end. A voltmeter appears to me to be a more reliable piece of equipment......especially when you're mix'in and match'in components. Dave
Mercedes (Bosch) Alternators Volker , we call AD generators " Alternators " as they produce Alternating current . Anyway , the ole you've chosen is a fairly crappy unit , it's rated @ 55 Amperes but will never produce that no matter what . SAAB 900's have a 87 Amp. (sometimes larger) current and have the very same fittment . BOTH of these Alternators are set to never exceed 13.6 VDC from the factory , I know one fellow who sells adjustable voltage regulators for them . Remember : the battery wire from the Alternator must pass through the ammeter before heading off to the battery or the ammeter will never work . The 30 Amp. ammeter in the dash is fine , it'll never charge more than that anyways unless you get a dead short or install a 2,000 watt stereo AND aircraft landing lights . I _highly_ agree that volt meters (think A-1 VW Golf , Carribe , Passat Cabriolet etc.) are much more useful and they don't require you to run the unfused charge current under the dashboard...
@nate Thanks for correction. Generator is a german word, i bend my head I think 55 amps are enough for an original truck. i don't have high power accessories on the truck and need the ammeter only for show. for my safety i have added a voltmeter, temp gauge and rpm-meter in the kick panel on the right side. Because all instruments are digital i can they see simple if i drive and if i stay by a car show and the ignition is off it seems the kick panel is black i installed a black foil (glass tinting) above the instruments. i will check the ammeter on weekend. could you say me how amps i need for little moving. i have a DC-charger with 10 amps and if i use a lamp with 35watts should it work?
Generator , Dynamo , Whatever I wasn't correcting you Volker , just trying to clarify so we're all on the same page.... Yes, that 55 A. AC Dynamo is plenty , it runs the heater , radio , head and fog lights (hey , this is L.A. , I gotta be STYLIN') plus charges up the HUGE 850 CCA battery a Mercedes Deisel requres , all just fine and dandy , I just don't like the 13.5 volts MAX thing , it idles @ 12 VDC . I'm not sure why you'd need a battery charger but 10 amps is plenty , way more than enough ~ remember : the slower you charge it , the longer the battery will last and the deeper the charge will be . I don't like digital gauges as they're not properly dynamic , I want an analog gauge (with needle) that instantly registers an change no matter how slight . I'd say you're in good shape Volker , go enjoy the show season , tech those young pups what REAL Trcking is all about ! .
Hey Nate. nevertheless many thanks for correction. only if anybody correct me i can learn more words And think about late summer - i go to the US and would be happy to meet a lot of people from this site. At the moment i don't now where i go. Recommendations? for nature and really american life. Where i was could you see on the pic. I need the charger not to charge my battery i thought i take this charger, two wires and a bulb to check the ammeter outside the truck. Therefore the question how many amps need the ammeter to moving. But the sun is shining today and i will drive not repair. go to the street now and if the battery is empty i can call my car service and they pull my truck at home Never, all my cars drive at home on the own axle with or without ammeter Volker
Vilkommen Volker ! If you make it to Ls Angeles , I'll buy you dinner . might not be fancy , I'm just an ex-farm boy .