I have a B1700 with a no charge issue. I' show 29.5 volts at 2500 RPM from the dynamo and have replaced the rectifier with an aftermarket one,the battery is recent and checks fine with a midtronics tester, cleaned the ground connection from the battery to the frame. I've check continuity on the wire (at least the one I could see) I have no charge light with an on key or otherwise, checked the bulb an continuity from the plug to the bulb contacts. I need some help where to go from here. Any volt or amp reading and where to take them would be helpful. I've been struggling with this for some time now been plugging it in to a battery maintainer when not in use. An halp or advice would be so welcome.
B1700 charging problem need specs
- Thread starter stevediers
- Start date
85Hokie
Moderator
Staff member
Lifetime Member
Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
With your volt meter ... check the voltage at battery, should be 12.6-12.7 tractor off......
Start the tractor - get RPMS up as tested before........ what reading DO you have at battery now?
Should be close if NOT over 14 volts..... IF same as OFF - then the "new rectifier is bad or a wire is open back to the battery. Any evidence of broken wire under dash? or from rectifier to source, a mouse could have chewed through a wire.
YOU cleaned the ground connections, but doing an OHM test is almost irrelevant on that large of a wire, it only tells you there is a open or closed path, NOT how good the path may be - a very small wire would show very little ohms at 2 feet, BUT you could have a bad connection INSIDE the joint, where the ends is crimped.
You said you replaced the rectifier ...... how did you know the old one was bad? 30 volts AC is a good sign, that says the dyno is working correctly. But really the only way to check that is to test output DC voltage.
Start the tractor - get RPMS up as tested before........ what reading DO you have at battery now?
Should be close if NOT over 14 volts..... IF same as OFF - then the "new rectifier is bad or a wire is open back to the battery. Any evidence of broken wire under dash? or from rectifier to source, a mouse could have chewed through a wire.
YOU cleaned the ground connections, but doing an OHM test is almost irrelevant on that large of a wire, it only tells you there is a open or closed path, NOT how good the path may be - a very small wire would show very little ohms at 2 feet, BUT you could have a bad connection INSIDE the joint, where the ends is crimped.
You said you replaced the rectifier ...... how did you know the old one was bad? 30 volts AC is a good sign, that says the dyno is working correctly. But really the only way to check that is to test output DC voltage.
Thanks for the reply. All I have at the battery is battery voltage even at high RPM. It was an after market rectifier I guess it could be crap. I replaced it when I tested and found that the dyno was putting out the right A/C volts and I was not getting a good reading at the battery. Took a chance. Is there a way to test at the regulator? Also I have not battery light on, how would I go about testing that? I know the bulb is good and continuity from the wires to the bulb connection.
I always like to check exactly what voltage you are measuring when testing the dynamo and if you are testing it disconnected.
You must use the AC voltage scale on your multimeter and the dynamo must be disconnected.
The WSM troubleshooting section suggests causes for No warning light.
Start by checking out the key switch for continuity between terminal #30 and AC.
There is a Truth table to determine if the regulator is OK. Any failure to meet the required condition means the entire regulator is not working.
Your test of the dynamo is producing lower voltages than the WSM expects. Having said that dynamo's rarely fail and further please confirm the way you did the test as mentioned at the start of this post.
As a basic wiring harness test, check for battery voltage along the circuit marked in red on the following wiring diagram.
Come back with what you find out.
Dave
Dave,
We've checked everything and all seems to be fine, my question is am I expecting to high of a charge voltage. We put the meter on and it seems to be bringing up the battery. We drew it down from 12.73 to 12.24 started it brought the rpm up to 2500 and saw the voltage start to go up incrementally back up to 12.9 before we shut if off. What are your thoughts. I was looking for like 13- 14 volts like a car alternator.
Steve
Dave,
Disregard my previous reply, I forgot the battery maintainer was still hooked up, back to square one. Just a note, the new rectifier was after market and all the wires don't match up, red and blues are the same the other two are not??
Do you still have the original regulator.
If you do consider doing the test on it just so we know it was bad.
Once you move beyond the early B series without a no CHARGE light, I have little faith in some of the On-line stuff being wired to fit a particular tractor. It is very easy for a vendor to provide a long list of models their stuff fits but then you are on your own.
This image of a rectifier is from Messicks site. How do the colors compare to your original one.
Dave
the books are jinglish, and IMO hard to follow.
thus I have my own tests
the regulator/rectifier has 6 wires. 2 are the same color, they end up at the dynamo. AC. One is a black ground wire. You will also have a +12v from the slow-blow fuse, and a +12v ignition (key on) and then a wire that runs to a charge lamp (if applicable, but it'll still have that wire).
Typically loss of charging performance is fairly easy to diagnose if you have the know-how, and a digital volt-ohm meter that has any quality whatsoever. A $10 one isn't that, just something else to throw into file 13 when it reads wrong.
The two dynamo wires (usually sky blue) are AC voltage, as said. Start engine, disconnect regulator and test ac output at the regulator connector, between the two dynamo wires. Should be 24V+ and I like to see more than 45 or so at full throttle. If it charges anything it's probably ok, they are a foolproof and extremely simple design that rarely fails outside of seized bearings. OK? Move on. Check your ground at the reg connector. One probe of the DVOM (set to ohms) on the ground pin in the connector and the other pin on a good ground, frame, transmission, etc. Must be clean. If you have more than a few ohms of resistance, your ground or harness is suspect
onward. Find your wire that comes from the battery. Backprobe the regulator connector. Now put your DVOM on DC volts. One probe goes to your connector, the other goes to the battery +. Should be under 500mv, or 0.500v. Ok? Move on. More than 0.5v? You have either a harness problem or a bad connection at the fuse, or whatever.
Last wire that will affect charging is what I call the "trigger" wire...it turns the reguator "on" so to speak, via the key switch. That one gets 12v when the key is on. Same as the last test, backprobe the connector with the key on. One probe of the DVOM in the connector and the other to the + battery terminal (use the post not the cable). You want to see less than 0.5v on the meter. If you see more than that, harness, fuse block, keyswitch, etc. Follow your wiring diagram. If you do see less than 0.5v, that circuit is not suspect, and there's a possibity you have a bad regulator.
Ideally you want to test everything AROUND the regulator because testing the reg itself isn't always conclusive. Thus, once you know you have AC voltage from the dynamo, you have good ground, you have +12v from the batt and ignition switch, the only component left is the reg. Process of elimination.
Electrical diag is not all that hard or it can be. It's all what you make of it. Don't put too much thought into it because it'll bite you. It's simple for the most part
speaking of being bit, be careful around the dynamo wires when testing. There's a little bit of voltage there and it's ac voltage, so it can bite you.
thus I have my own tests
the regulator/rectifier has 6 wires. 2 are the same color, they end up at the dynamo. AC. One is a black ground wire. You will also have a +12v from the slow-blow fuse, and a +12v ignition (key on) and then a wire that runs to a charge lamp (if applicable, but it'll still have that wire).
Typically loss of charging performance is fairly easy to diagnose if you have the know-how, and a digital volt-ohm meter that has any quality whatsoever. A $10 one isn't that, just something else to throw into file 13 when it reads wrong.
The two dynamo wires (usually sky blue) are AC voltage, as said. Start engine, disconnect regulator and test ac output at the regulator connector, between the two dynamo wires. Should be 24V+ and I like to see more than 45 or so at full throttle. If it charges anything it's probably ok, they are a foolproof and extremely simple design that rarely fails outside of seized bearings. OK? Move on. Check your ground at the reg connector. One probe of the DVOM (set to ohms) on the ground pin in the connector and the other pin on a good ground, frame, transmission, etc. Must be clean. If you have more than a few ohms of resistance, your ground or harness is suspect
onward. Find your wire that comes from the battery. Backprobe the regulator connector. Now put your DVOM on DC volts. One probe goes to your connector, the other goes to the battery +. Should be under 500mv, or 0.500v. Ok? Move on. More than 0.5v? You have either a harness problem or a bad connection at the fuse, or whatever.
Last wire that will affect charging is what I call the "trigger" wire...it turns the reguator "on" so to speak, via the key switch. That one gets 12v when the key is on. Same as the last test, backprobe the connector with the key on. One probe of the DVOM in the connector and the other to the + battery terminal (use the post not the cable). You want to see less than 0.5v on the meter. If you see more than that, harness, fuse block, keyswitch, etc. Follow your wiring diagram. If you do see less than 0.5v, that circuit is not suspect, and there's a possibity you have a bad regulator.
Ideally you want to test everything AROUND the regulator because testing the reg itself isn't always conclusive. Thus, once you know you have AC voltage from the dynamo, you have good ground, you have +12v from the batt and ignition switch, the only component left is the reg. Process of elimination.
Electrical diag is not all that hard or it can be. It's all what you make of it. Don't put too much thought into it because it'll bite you. It's simple for the most part
speaking of being bit, be careful around the dynamo wires when testing. There's a little bit of voltage there and it's ac voltage, so it can bite you.