Volvo Community Forum. The Forums of the Volvo Owners Club

Forum Rules Volvo Owners Club About VOC Volvo Gallery Links Volvo History Volvo Press
Go Back   Volvo Owners Club Forum > "Technical Topics" > PV, 120 (Amazon), 1800 General

Notices

PV, 120 (Amazon), 1800 General Forum for the Volvo PV, 120 and 1800 cars

Information
  • VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. You need to register in the normal way
  • AOL Customers: Make sure you check the 'Remember me' check box otherwise the AOL system may log you out during the session. This is a known issue with AOL.
  • AOL, Yahoo and Plus.net users. Forum owners such as us are finding that AOL, Yahoo and Plus.net are blocking a lot of email generated from forums. This may mean your registration activation and other emails will not get to you, or they may appear in your spam mailbox

Thread Informations

Alternator not charging

Views : 2036

Replies : 6

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Sep 5th, 2018, 09:01   #1
Uplander
Member
 

Last Online: Dec 21st, 2023 10:01
Join Date: Jul 2016
Location: Bridport
Default Alternator not charging

Hi
I have a 1969 1800S (B20) with a SEV Motorola Alternator and don't have any charge going to the battery.
The battery is fairly new and I have a shut off switch fitted on the negative side which I always use when putting the car away in the garage. The AMP light hadn't been coming on when turning on the ignition and on investigation one of the piggyback connectors had come off the external regulator. Now the AMP light works but stays on when the engine is running.

Voltage tests as follows:
With engine off:
Battery (not fully charged) 12.1v

With engine running:
Battery 12.1v
Alternator cable to starter solenoid 12.1v
Alternator connection from regulator: 0.89v

There is no change in voltage when engine speed is increased.
I've looked at Ron's tests for a Dynamo and VR, but not sure if these apply to Alternator set up.
What's the best way to determine whether it's the alternator or the regulator that is at fault?
Thanks
Simon
Uplander is offline   Reply With Quote
Old Sep 5th, 2018, 10:24   #2
Ron Kwas
Premier Member
 
Ron Kwas's Avatar
 

Last Online: Today 19:07
Join Date: Jul 2007
Location: Connecticut, USA
Default

Simon;

Generator/Dynamo info is definitely not applicable...so don't look at that...but rather look at Alternator info for 123GT info here: https://sw-em.com/123GT_Charging_System_Notes.htm ...as you may know, the 123GT also had an SEV Motorola Alt...so much of this info will be applicable**!

...and now that you're in the correct reference place, I expect the wire which was disconnected was from AMP Ind to 61 on Alt...this would cause AMP Ind not to function, but Alt and Reg to remain functional (in self-excitation mode)...now that you've reconnected this wire, non-rise in voltage when raising RPMs, as well as AMP Ind being continuously ON pretty much confirms Chg Sys is no longer working... I suggest you read and understand the theory of operation at link, then proceed to Troubleshooting Notes...

Good Hunting!

** Edit: In thinking about this a bit more...your '69 1800S with Alt sounds somewhat unusual...'69 was the changeover year to injection, and the later (140 style) multi-Fuseblock and Alternator (wiring diagram as here: https://sw-em.com/1800E%20Wiring%20Diagram.jpg )...OR do you have the earlier harness (only 3 Fuses) but with an Alternator fitted (unusual combination!)? ...normally the earlier harness would have had a Generator/Dynamo fitted...I am not aware of the earlier harness/Alt combination from the factory, and as far as I can recall, I have never seen a wiring diagrams showing this combination... Please confirm configuration of this vehicle is as delivered from the factory and unmodified (as best you can)...if modified, current configuration must be very carefully established to allow valid troubleshooting...

Last edited by Ron Kwas; Sep 5th, 2018 at 11:39. Reason: Additional Info
Ron Kwas is online now   Reply With Quote
The Following User Says Thank You to Ron Kwas For This Useful Post:
Old Sep 5th, 2018, 13:01   #3
Uplander
Member
 

Last Online: Dec 21st, 2023 10:01
Join Date: Jul 2016
Location: Bridport
Default

Thanks Ron.
I have the 3 fuse harness (other changeover items include B20 engine, still on carburettors, later steering wheel, cable operated clutch - what else?) But I couldn't say for sure that the configuration is as factory built.
I haven't seen a wiring diagram that covers both either, I've looked at diagrams from the S for colour coding and the E for the alternator to understand the layout.
Simon

Last edited by Uplander; Sep 5th, 2018 at 13:04.
Uplander is offline   Reply With Quote
Old Sep 6th, 2018, 16:54   #4
Ron Kwas
Premier Member
 
Ron Kwas's Avatar
 

Last Online: Today 19:07
Join Date: Jul 2007
Location: Connecticut, USA
Default

Simon;

Again, that is either a highly unusual combination from the factory OR someone's Alternator conversion...so I can't be certain of wiring configuration around the Alt, or even if it is an Alt with External or Internal V Reg.
Only by careful inspection of wiring will you be able to determine this, and this will be necessary to know to proceed with troubleshooting on the vehicle...I expect wiring to resemble that shown on 123GT page (for external V Reg) OR this extract from 1800E (also ext. V Reg, https://sw-em.com/1800E_Wiring_Diagr...ys_Excerpt.jpg), OR this (generic GM Chg Sys config with internal V Reg, https://sw-em.com/gm_charging_sys.htm )

I suggest a careful inspection, and recording (including color codes) of what you have and either posting it here or contacting me directly per e-mail (don't use forum messaging!)...some pictures of Alt and Reg wouldn't hurt...of course, you could simply remove the Alt, take it to a elec service shop and have them check it stand-alone...but that is little progress when they tell you "...it works fine!". I recommend testing in situ, which will allow narrowing it down to Alt or VReg.

Good Hunting!
Ron Kwas is online now   Reply With Quote
The Following User Says Thank You to Ron Kwas For This Useful Post:
Old Sep 8th, 2018, 19:20   #5
Pigeon
Volvo-loving biker
 
Pigeon's Avatar
 

Last Online: Feb 3rd, 2019 05:24
Join Date: Sep 2006
Location: All alone in the crazy city
Default

Quote:
Originally Posted by Uplander View Post
external regulator
If it is a conversion, make sure that this has indeed been changed to an alternator type. If someone has tried to keep the original dynamo regulator, then anomalous operation is to be expected. It probably isn't this because they'd have to be quite thick not to have noticed the problem themselves, but it's worth checking in case they were also too thick to twig what they'd done wrong.

Having got that out of the way...

Disconnect the wire to the DF terminal on the alternator, then, with the engine running, connect the DF terminal to battery positive via an indicator bulb (21W) while measuring the alternator output voltage at the B+ terminal. What happens? What you should see is that the output voltage rises. It might rise rather high, but that won't matter as long as you don't maintain the connection for longer than is needed to get a reading. You should also hear the engine speed drop slightly because the alternator will be taking mechanical power, and the AMP light should go out.

If that's OK, then put the wire to DF on the alternator back; then disconnect the wires to the DF and D+ terminals on the regulator, and connect them together. Again, you should see the voltage on B+ rise, hear the engine speed drop, and see the AMP light go out.

If the first test fails, almost certainly the alternator is knacked.

If the first test is OK but the second one fails, probably the alternator is knacked.

If both tests are OK, it's probably the regulator.

To hear the change in engine speed, it may be useful to do the tests with the headlights and/or the heater fan on, to make sure there is a decent load on the electrical system.

That should be enough, but do post back with the results, because there is always the possibility of unexpected weirdness.

The wiring is a lot simpler than the diagram in the book makes it look (this is always the case with car electrics, because the published diagrams attempt to depict the physical layout of the components and the loom, as well as the electrical topology). Electrically, it looks like this:



"Generating device" is either a dynamo or an alternator.

The node labelled "dynamo only" does not exist in an alternator system; the node labelled "alternator only" does not exist in a dynamo system.
__________________
Pigeon's Nest

Be kind to pigeons
Pigeon is offline   Reply With Quote
The Following 2 Users Say Thank You to Pigeon For This Useful Post:
Old Sep 19th, 2018, 12:13   #6
Uplander
Member
 

Last Online: Dec 21st, 2023 10:01
Join Date: Jul 2016
Location: Bridport
Default

Thanks for all the suggestions.
Cleaned all the connections thoroughly but light remained on so postponed further tests until the following weekend. Come Saturday I took it for a drive and noticed the light had gone off. Tested the voltages when I got home and the alternator is now charging the battery with healthy readings all round.
I will keep an eye on it though.
I will send some photos in due course to you Ron for peace of mind.
Thanks Pigeon for the comprehensive tests, I'll keep this by for future reference as will other members I'm sure.
Simon
Uplander is offline   Reply With Quote
The Following User Says Thank You to Uplander For This Useful Post:
Old Sep 19th, 2018, 15:17   #7
Ron Kwas
Premier Member
 
Ron Kwas's Avatar
 

Last Online: Today 19:07
Join Date: Jul 2007
Location: Connecticut, USA
Default

Simon;

Thanks for follow up...if symptoms return, check Brushes...worn brushes start making themselves known by intermittent charging...otherwise, your connection cleaning efforts may have payed off!

Cheers
Ron Kwas is online now   Reply With Quote
The Following User Says Thank You to Ron Kwas For This Useful Post:
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 19:50.


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.