Benford Dumper 2500 – Electrical question
Started by finnmac
Viewing 15 posts - 1 through 15 (of 15 total)
Saturday 26 March 2011 at 17:04
HiIf anyone can help us with a wiring question on a 1988 Benford 2500 we’d be very grateful. We surprised some kids playing around the dumper last week and now there are two wires loose around the starter motor and we would like to know where, if anywhere, they should be replaced to keep the battery charged.Wire 1 (marked as A):In the accompanying picture, the cable coming from the battery + terminal is marked (+).There is a loose wire (A) which connects on one end to the battery + terminal via the connection on the back of the solenoid (B).The unattached end of it is a female spade connector (C).There are male spade connections top (D) and bottom (E) of the heat sink bolted to the engine. The connector at top of the heat sink (D) is actually snapped off, so I’m hoping this *isn’t* where C attaches!The two wires (F) leading to the heat sink come, I assume, from the dynamo on the engine but I’ve no experience with these engines or with this type of wiring setup.So, does C connect somewhere on the heat sink? If so, where?Wire 2:Just out of picture is a short piece of wire bolted on one end to the chassis (i.e. a negative or ‘earth’ connection). The other end of it is a female spade connector. The only male connector within reasonable range is the one on the back of the solenoid (G). However, the dumper is starting fine on a turn of the key without this wire being attached to anything! Should it be attached or is it just redundant?We’ve already replaced the cylinders on this dumper and it’s running fine, but electrics are a bit of a mystery and we want to get them replaced absolutely right.Thanks for any help!RegardsStan0#957922
Saturday 26 March 2011 at 17:36
Hi Stan, how are you?
Wire 2: Should NOT be connected to Terminal G on the starter. Will it reach the E terminal on the heat sink? If not leave it as it is.
Wire 1: It probably is not charging the battery? The flying wire C should be connected to a terminal called +. Which is the same as the broken terminal D.
If you get a lend of a cheap multimeter (5-10 pounds) select DC Voltage and connect the red lead to the positive battery terminal and the black lead to the negative battery terminal. Start the engine and you will find that the voltage stays around 12volts?
Now tip wire C to D and watch to see if the voltage rises? If so just put a double connector onto terminal D to take the two wires. Maximum voltage when running is around 15 volts. But if it rises over 12 its charging the battery.
Now, the only thing to watch for is a drain on the battery when you stop the engine. So with the engine stopped disconnect wire C again and watch for a very small spark when you reconnect. If you have a spark your battery will go flat overnight.
Kids are best admired from a distance
Try the above and get back to us.0
Sunday 27 March 2011 at 11:50
Sunday 27 March 2011 at 12:23
Hi Stan, could you send me a picture of the wires coming out of the dynamo, please?
One of the wires from the dynamo to the regulator (thats what the heat sink is) will be for charging the battery. This will be the heavier of the two wires.This wire is usually given the name D or D+ ?
The other wire controls when the dynamo works. Switching the power to the dynamo on and off, therefore regulates the output voltage to around 15volts. This wire is usually called F (because it goes to the field windings in the dynamo) ?
The broken wire usually connects to a terminal called B or B+? Because it goes to the battery
Yes you probably can reconnect the broken wire but it wont be easy.Soldering a wire on after cutting away the surrounding insulation is your only hope.
But tip it to the broken terminal on the heat sink/regulator first to see if it works temporarily. You may well have to get a new regulator if all the terminals are about to break off. It wont charge the battery without it
PS Good work uploading the pictures, had you to go through the picture gallery?
Sunday 27 March 2011 at 13:19
The photos are being uploaded to a hosting server and then linked to these posts (we have someone here who builds web sites).
I’m afraid that the wires disappear into the engine block (see upper photo) at point G. So that’s as far as I can trace them.
HOWEVER, when i lifted up the two wires I found two others (clearly redundant) stuck in the fins below! (See lower photo). God knows what they were/are.
>The other wire controls when the dynamo works. Switching the power to the dynamo on and off, therefore regulates the output voltage to around 15volts. This wire is usually called F (because it goes to the field windings in the dynamo) ?>
Thanks again for your help on this. Having helped on forums myself I’m aware of the effort involved.
Sunday 27 March 2011 at 19:35
The only reason I asked for a picture of the dynamo was to check it was a dynamo and not an alternator? As the machine is a bit young to have a dynamo.
Yes it senses when the overall voltate is going above 15volts and starts to switch on and off. The sensor is actually a zenor diode inside the regulator.
No not sure of the regulator type, look for numbers/name on the sides when you take it off.
But we can always do more tests to find out which replacement will work.
One will control the supply to the field windings (or the positive wire to the fields)
The other will control the return from the field windings (or the negative wire to the fields)
You can not mix and match
We are based in Ireland so I don’t know the availably of parts in the UK
Monday 28 March 2011 at 14:04
Friday 15 April 2011 at 17:26
Having now kept this dumper under observation while in operation, I’m of the opinion that the battery is not being charged properly. Across the battery terminals there is now a consistent current of about 12.5 v no matter the engine speed. I’ve called a couple of suppliers in UK to try and establish some info about replacement parts but they were unable to help until i had identified what the specific parts were that needed replacing/repairing.
I wonder if I can ask for your help with the following to try and help me diagnose what I need to replace?
1. What test, if any, can I run on the 2 wires coming out of the alternator/dynamo housing to be sure that it is supplying the necessary power? i.e. how do i eliminate the alternator/dynamo as the source of the problem?
2. Is there any way for me to test that the 2 wires from the alternator/dynamo have been connected to the proper terminals on the voltage regulator?
3. Assuming I need to replace the voltage regulator, is there ay way for me to identify what kind of replacement to ask for? There is absolutely nothing written or stamped on the old one, and the supplier I spoke to this afternoon gave a shrug and said: ‘How am i to supply a replacement if I don’t know what the old one is?’
In essence, I want to fault find through the system from alternator to battery, establish what isn’t working, and then try and source a replacement in UK and have it shipped out to France.
After that, i want to identify the local kids who ripped out the wiring and have them shipped to Devil’s Island.
Any help received with gratitude because currently we are recharging the battery twice a day with a portable generator and charger to keep it topped up so it doesn’t break down on site (which is a mile from the nearest recovery equipment).
Saturday 16 April 2011 at 18:59
The 14.5v is all you get and want from the system to charge your battery. If it started to work now doesnt, have you not just got a bad connection somewhere?
Saturday 16 April 2011 at 19:55
Hi Stan, yes you are correct it is not charging if the voltage does not go higher than 12.5 volts.
I never did see the alternator/ dynamo any chance of a pic?
Probably your best bet will be to fit a secondhand alternator in place of the original as it will have everything built in. One big wire to the battery and one small wire to the ignition switch, how does that sound? Go for a LUCAS off any old Ford etc.
The only problem will be to ensure the belts are the same and they line up OK
I know it sounds a bit extreme but those external regulators are very difficult to fault find even on a good day and as you don’t have a wiring diagram it will be next to impossible. As you have already done all the easy stuff, haven’t you?
I’ll have a bit of a think and get back to you.
PS Sorry I didn’t reply as we were under a bit of pressure at work.
Edit1: I see you were getting 14.5 volts in an earlier post, would you have a new bad connection, “Wiggle” the wires to see if it starts to charge.
Sunday 17 April 2011 at 09:41
Sunday 17 April 2011 at 14:17
You should get an AC voltage from the winding in the engine. So make sure the voltmeter is on AC, then connect red lead to the larger of the two wires and black to the engine casing. Rev the engine up and you should see the voltage rising up to around 15 to 20 volts?
Now depending on the internal setup you may have to connect the smaller wire to get voltage from the big one. But unfortunately I don’t have enough information to tell you how to connect it up.
I will try to locate a wiring diagram for you if I can.
Sunday 17 April 2011 at 17:29
Thanks for that. I’ll try it as soon as the dumper gets back. I think I’ll try and speak with Lister-Petter again and try to get some info on the windings, possibly with a wiring diagram, because we really are flying blind without one, aren’t we.
Monday 18 April 2011 at 17:40
Spoke to Lister-Petter again and this time got a very helpful guy from servicing. Between your test and his checklist we are able to determine that there is intermittent voltage from the windings. The guy at LP thinks that an oil leak behind the flywheel/rotor may be shorting out the windings (the oil leak has been worsening over the last 3 weeks, thereby perhaps creating a new problem to supersede the old). So, a full visual inspection will be required, after the clutch housing has been removed.
Thanks again for all your help on this. Without it we couldn’t have got to this stage.
All the best
Monday 18 April 2011 at 23:13
Glad to be of help.
Pity about the oil leak.
At least the kids can walk the streets again !
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