QuestionHi there, and thankyou for your response. I'm from all the way in Scotland by the way! I've now established that the dynamo is working and good power is coming out of it. However, this power is not reaching and charging the battery. The wiring is not in the best condition but was wandering if it could also be the voltage regulator, or if theres anyway to test whether it is the voltage regulator?
Cheers, Matt
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Followup To
Question -
hi, would you be able to help me with my ford popular 100e? I just got it a couple of days ago and dont know much about cars. There was a problem the charging of the battery and some other people I spoke to and myself thought it was the dynamo. So I replaced the dynamo but the warning light is still coming on and it doesnt seem to be charging the battery when I jump started the car. I was told by someone I might need to prime the dynamo. I'm not sure if I did this correctly or whether its just another problem. Hope you can help,
Cheers
Matt
Answer -
Hi Matt, I'd be happy to help you.
I'll assume you live far, far away from me, since I've very, very rarely heard the term dynamo used regarding cars. I'm in California, USA, where are you and that lovely "mature" Ford you just acquired?
The first issue is this. It's true that a dynamo (or generator as I call it) will re-charge a battery while you are out driving hither and yon...but it's purpose is not to take an undercharged battery from 9 or 10 volts up to 12+. So...just so we are talking common terms, every test you make henceforth should be with a fully charged battery, like in the range of 12.8 volts. If you don't have a good battery charger, this situation is the best excuse for buying a good one.
I'll start describing the trouble-shooting you'll want to do...but as my typing is fairly slow...I'll stop once in a while to let you complete the testing and let me know what you're finding. OK?
Please forgive me if I cover the obvious, but I want to ensure we've eliminated the simplest possibilitites first.
1. Check the dynamo's drivebelt tension.
2. Also, make sure the dynamo is securely fixed in position... a missing or loose mounting bolt could affect the belt tension.
3. Re-do every wire connection at the dynamo and the voltage regulator. This means disconnecting each in turn...with the battery disconnected!...cleaning corrosion and grime from the terminal and the connector so they are shiny again.
4. There should be a ground wire at the voltage regulator. Definitely re-do this connection (as in #3 above) and ensure the spot where the wire is grounded is actually grounded. There are two ways to do this.
Let's say the wire is attached to a metal inner fender. You must be able to trace that attachment point all the way over to the battery's ground terminal. Said another way...that fender has to be connected via friction or an existing wire ultimately with that battery ground terminal. So you should see a wire from the fender to the frame and from the frame to the battery. Right? In those cases where the frame touches the fender because it was built that way...there is an assumption the fender will be grounded because the frame is grounded... and the frame is touching the fender. But what happens it there is a layer of rust or dirt between the two? No ground...or bad ground.
The other way to test this condition is to buy a multimeter that will tell you when you touch its probes to both the fender and the frame simultaneously, that the "continuity" is perfect. Often the meter will display .000 as perfect and 1.000 as no continuity. You are not going to accept .001 or .002 as good. More cleaning and scraping and shining will be required.
Let's stop there and I'll let you get to work. Write back to me to let me know how it's going!
Dave
AnswerHi again. Scotland! Thanks for being my first Scot.
Sure, there are ways to test the regulator...but...if the wiring is truly bad, you may replace a perfectly good regulator when you don't have to. There!...that's enough preaching about wiring on my part!
Test 1. Assuming to have a 12v+ test light (that when you touch its probes to the two battery terminals (positive and negative) the light comes on.
Disconnect the battery's negative (ground) cable. Connect your test light to that loose cable end and the now empty negative battery terminal. If the light comes on, there's a constant drain from the battery (some component is always on when it shouldn't be). This shorted condition should be corrected before the charging system is tested more fully.
Test 2. Assuming you have a multimeter or a voltage reading device.
Re-check the battery voltage at rest. It's 12.5-12.8 right? Start the engine and let it warm up a tiny bit. Increase the engine speed to over 2000 rpm and check the battery voltage again. Now it should read 14-15 volts. I assume this is the point you've reached...not seeing the battery getting dynamo current....
Test 3. Vehicle at rest. Turn the ignition key on, but don't start, and verify the dynamo indicator light is on. If it isn't on there's a chance the indicator wiring circuit is faulty... and some are wired in such a way as to disrupt the dynamo's performance. DUMB!
If the light isn't on, re-checck the regulator ground wire.
Test 4. This is known as a "full-field" test...and I'm reluctant to explain all the details without seeing how and how mant connections there are at the dynamo and the regulator. Could you send me some infromation that would describe in words what connections to and from what and where are at the dynamo and the regulator? --OR--
If the following makes sense, skip the note back to me and do the following "full-field" test. Conceptually, you are bypassing the regulator and letting the dynamo have direct contact with the battery. This should be done in minimal time increments...just enough time to get readings, then stop and rest. If you bypass the regulator and the battery (after revving the engine over 2000) begins to get 14-15 volts, then the regulator is indeed bad. Again, the "full-field" test takes the regulator out of the circuit... and since it's primary function is to prevent high voltage spikes from the dynamo that could damage some electrical components, be careful to monitor the voltage readings...you're looking for 14-15 volts, NOT 16.
Let me know how it goes.
Dave
