check voltage regulator

I've just purchased a 30 year old gasoline engine forklift...
I note that the machine never seems to go off fast charge, by the machine's
A-meter. This is the old style voltage regulator style unit. I know nothing
about them. Are there any easy checks to know if the regulator is working
correctly?
Reply to
Karl Townsend
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If it's a 6 or 12 volt battery and a "real" DC generator, not an alternator, then:
Put a good voltmeter directly across the battery while the engine is running and you are seeing the ammeter showing a high charge rate.
If you read less than about 7.2 on a 6 volt system or 14.8 volts on a 12 volt one then the battery isn't yet fully charged and the high charging current is just trying to charge it.
How olde is the battery? It may be a junker and never really reach it's full charge voltage. You can test that by charging it for a good long time with a line powered charger.
I don't recall any "easy" way to "prove" an old style voltage regulator is OK and adjusted properly. Many of them had screwdriver adjustments inside which changed the tension on springs. If someone who didn't know his ass from his elbow got inside and F'd those adjustments up they'd have to be reset. You'd need a high current variable voltage source, a variable high current load resistor and decent voltmeters and ammeters to be able to do a thorough "bench test" of one of those beasts.
Most of those old regulators had three relay like devices in them. One was a "cutout" which opened the charge path to the battery when the engine was stopped, so the battery didn't try and motor the generator, burning something up. It could be replaced by a hefty solid state diode nowadays and accomplish the same thing.
The second was a voltage operated relay with normally closed contacts which opened the field supply to the genny when the output voltage got high enough to mean the battery was fully charged.
The third was a current operated relay with normally closed contacts which sensed the genny's output current and opened the field supply to the genny if that current got higher than the sytstem's design limit.
I recall seeing some "Two relay" voltage regulators where the functions of the voltage sensing and current sensing relays were combined into one relay with two coils on it.
Thas' about all I recall about them.
If it's an alternator system with a separate voltage regulator ask a youngster.
Jeff
Reply to
Jeff Wisnia
"Karl Townsend" wrote in message news:B1kIg.2168$ snipped-for-privacy@newsread4.news.pas.earthlink.net...
Hi Karl
This problem will be real easy for you to solve.
I suspect you have an alternator on the 1976 forklift. Measure the battery's terminal voltage while the forklift is charging. If the battery voltage is below 14, the system may be charging properly.
Note, it is easy to install a solid state regulator in place of the "old style" (mechanical relay type regulator).
Jerry
Reply to
Jerry Martes
Correct.
OK, at 3/4 throttle I'm up to 18.5 volts. Then the neg probe rattled off, hit the fan, and got mangled :( Time for new parts?
I've not done this, just a replacement part to order?
On my tractor, when I fried an alternator due to this, I just replaced the alternator with the GM style alternator with regulator included. Is this a better route? Then, I have a new alternator also.
Karl
Reply to
Karl Townsend
"Karl Townsend" wrote in message news:OOlIg.2203$ snipped-for-privacy@newsread4.news.pas.earthlink.net...
Hi Karl
If you can mount a Delco alternator with internal regulator in place of the one thats now on the forklift, do it. It is likely that you could put a new voltage regulator on the one you have on the forelift now, and that alternator will work. For now, disconnect the field wire from that alternator. This is a good time to get a new battery too. Any battery that allows an alternator to get its terminal voltage up to 18.5 volts is too close to being unreliable.
If, for some reason you want to replace only the regulator, I can get one for you (no$$).
Jerry
Reply to
Jerry Martes
I'll second the Delco alternator recommendation. I did the same thing on a backhoe that originally had a 55A Motorola alternator with external regulator. Just put an 85A or so Delco in it's place for about $20 from the salvage yard.
Pete C.
Reply to
Pete C.
I would stop using this machine until you solve the problem. A farm friend stopped by one day and said "gee, my alternator belt is screeching and I can't tighten it up enough to make it stop." I checked that voltage at the battery and it was 16.5. I told him to go get it fixed right away because at the minimum he would likely blow out bulbs, etc. He didn't. A week later, while waiting at a red light, the whole truck burned up.
Pete Stanaitis -----------------
Karl Townsend wrote:
Reply to
spaco
Pretty much how I got my current truck . The owner finally got tired of paying a shop to install new coils , alternators , regulators and electronic ignition modules along with paying tow truck drives . The truck was putting out 18 volts and toasting everything . I never did find out exactly where the problem was as the wiring was a rats nest . I rewired it and the problem went away . Maybe try mocking up a small loop eliminating as many circuits as you can . If it tests OK add circuits until the problem resurfaces . Luck Ken Cutt
Reply to
Ken Cutt
Follow-up. NAPA now sells a unit just for tractor retrofit. Just one wire to connect, the large one to the A-meter. Cost was $50 with a $15 core return credit = $35. Problem solved.
Karl
Reply to
Karl Townsend
Hmm. But the hourmeter/tach on the diesel is fed from the back of the generator (yep, generator, at least according to the manuals - whopping 22 amp unit), which has been disconnected along with ~98.2% of the wiring on the tractor since before I got it. I could get a replacement electro-mech VR, but I don't find the concept appeals much. On the other hand, it would be nice to actually charge the battery in the tractor, permitting me to use the correct size battery, as opposed to the wal-mart car battery that had been retrofitted, and which comes home to sit on the battery charger on a regular basis.
Reply to
Ecnerwal
I didnt get the original message that included a reference to the problem of running a tach from the signals available from a "generator". So, this Top Post seems appropriate.
"generator" It is common for an Alternator to be referred to as being a Generator. Alternators are referred to as AC Generators in Delco texts. The half wave rectified stator voltage from a 3 phase Alternator (with a diode trio) is often used to provide an AC voltage whose frequency directly relates to engine RPM. If you had an alternator with the same diameter pulley as was on the original alternator, any alternator can be used for the tach signal generator by connecting to its diode trio. That might involve installing a diode trio on some alternators. But that isnt difficult.
"whopping 22 amp unit" Most Utility vehicles, like forklifts dont include alot of electrical load while running. They need mostly to only replace the charge lost during start cranking. So, Low Current rated alternators are sufficient. High current rated alternators commonly have Delta Connected Stators. Low current rated alternators are Star Connected Stators. An alternator with a Star Connected Stator will provide a given output at a lower RPM than an alternator with a Delta Connected Stator.
Jerry
Reply to
Jerry Martes
Well, you did get "the original message...running a tach", as that was something I brought up in the message you replied to, not something Karl mentioned.
The tach/hourmeter in question is run by a mechanical drive, similar to a speedo cable, so it works fine now when the only part of the electrical system that works (or is even connected) is the starter motor. Thus, if I replace the generator with the otherwise nice solution Karl found, I lose the tach/hourmeter (not that the hourmeter means much, as it's was disconnected for god knows how long at some prior point in its life - but it does give me service interval info). Besides which, at some point I made a basic investigation of my generator and it does put out voltage - it just needs regulation. The old electromech regulator is full of paint (bad spraypaint job done at some point, cover missing, whole thing covered in yellow), and suspect even before that problem. Old tractor parts places have the exact replacement, but I'm frankly more comfortable with a solid state solution.
Reply to
Ecnerwal
Hi
I am only guessing now, but it might be that your tractor has a DC generator that includes a mechanical drive for the tach. There are alot of types of DC generators, so there is no way to know which type you have. If you knew the type of generator, it would be easy to get a voltage+current regulator. Have you considered leaving the DC generator in place to drive the tach but disconnect its electrical, then add a small alternator?
Jerry
Reply to
Jerry Martes
I'd be tempted to clean up the regulator contacts with a points file and see if it helps...
--Glenn Lyford
Reply to
glyford
I think some of the replacement regulators are actually solid state, but I do not know which ones. The mechanical regulators are actually very reliable and were used for many years on probably millions of vehicles. They can be cleaned and adjusted. I think you would be perfectly happy with a correct replacement regulator.
Don Young
Reply to
Don Young

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