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" > 700/900 Series General

Notices

700/900 Series General Forum for the Volvo 740, 760, 780, 940, 960 & S/V90 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 upgrade

Views : 8607

Replies : 145

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Oct 27th, 2019, 12:26   #21
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Yesterday 21:57
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by 940volvoman View Post
Towbars,indeed!!


However the split charge relay and other associated bits aren't used,so could be removed.....

Thanks for the immobiliser info.Will reply by pm asap
Good idea removing the split charge relay, would be worth checking the output/charging voltage after you've removed it.

No worries on the immobiliser, i guessed you might not be up to 30 posts yet so perhaps couldn't send a PM so sent it anyway.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 27th, 2019, 13:34   #22
Stephen Edwin
Premier Member
 

Last Online: Oct 26th, 2023 21:42
Join Date: Jun 2010
Location: Thurrock
Default

It is a bovversome and I think expensive problem. I wish you all the best re sorting it.

I offer two points that I believe do no harm.

If the battery loses its flavour on the bedpost overnight. Disconnecting the earth strap is no faff at all. Ahem. Always disconnect the earth [first].

The towing electrics have a mixed history. Whether they are implicated here or not they are a potential problem. Is there any good and compelling reason not to remove them completely?

Good luck.



P.S. Yes. Please avoid replacing parts unless there is a real reason.




.
Stephen Edwin is offline   Reply With Quote
The Following User Says Thank You to Stephen Edwin For This Useful Post:
Old Oct 27th, 2019, 13:40   #23
TonyS9
Premier Member
 

Last Online: Mar 4th, 2024 00:49
Join Date: Jul 2009
Location: Holywood
Default

My parascitic is about 100mA (i have a permanently powered mpg meter in addition to alarms and clocks), should be no problem for a few weeks.

Most likley your problem is charging, 13V at the battery (across the baterry ternminals, not chassis to +) means 50% charging rate, you need at least 30min min drive per day to get charged.

Forget parasitic, forget bigger alternators, sort the charging voltage.

Last edited by TonyS9; Oct 27th, 2019 at 13:43.
TonyS9 is offline   Reply With Quote
The Following 2 Users Say Thank You to TonyS9 For This Useful Post:
Old Oct 27th, 2019, 13:59   #24
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Yesterday 21:57
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by TonyS9 View Post

Forget parasitic, forget bigger alternators, sort the charging voltage.
Hence my comments further up about the rectifier and the test for it (without needing to strip the unit down) of disconnecting the B+ wire from the alternator overnight. I forgot to say to be careful when doing it not to short the spanner to earth (it *%$@ing hurts!) and to wrap some insulating tape round the terminal so if the cable sags overnight, it doesn't short to earth and cause a fire.

Yes, it's a faff to do it but it isolates the laternator as the culprit if it doesn't discharge so much. The rectifiers are known to go on these, usually only on one leg but that's enough to impact the charging voltage (AC out of the alternator isn't good!) and cause a parasitic drain.

The rectifiers also fail on the later Nippon Denso units but these are generally more sneaky and develop an intermittent fault causing an intermittent battery drain which won't happen for ages then will suddenly cause problems.
On the upside, the Nippon Denso are usually battery sensed animals so are easy to modify with one external component to charge calcium batteries effectively.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby For This Useful Post:
Old Oct 27th, 2019, 14:14   #25
Stephen Edwin
Premier Member
 

Last Online: Oct 26th, 2023 21:42
Join Date: Jun 2010
Location: Thurrock
Default

Quote:
Originally Posted by Laird Scooby View Post
I forgot to say to be careful when doing it not to short the spanner to earth (it *%$@ing hurts!) and to wrap some insulating tape round the terminal so if the cable sags overnight, it doesn't short to earth and cause a fire.


.......
Stephen Edwin is offline   Reply With Quote
Old Oct 27th, 2019, 18:54   #26
940volvoman
Master Member
 

Last Online: Mar 25th, 2024 19:11
Join Date: Mar 2017
Location: Burgess Hill
Default

OK,,, Thanks for all the continued support. A frustrating problem made easier with help from friendly contacts.

The rectifier is included in the voltage regulator (2 problems sorted in one here...) The rectifier being the diode that flattens the current curve.

The voltmeter i fitted is an analogue one. Unless I replace it with a digital one I cant be exact about the voltage the battery is receiving. However, today the gauge was showing a very healthy 14ish volts dropping once the battery replenished. As I have added (not replaced) extra cables from the alternator to the battery + and -,the voltage at the battery and alternator should be the same,almost without any voltage drop.
940volvoman is offline   Reply With Quote
The Following User Says Thank You to 940volvoman For This Useful Post:
Old Oct 27th, 2019, 19:23   #27
mocambique-amazone
Master Member
 

Last Online: Jan 24th, 2022 18:08
Join Date: Nov 2008
Location: small village in the north of Germany
Default

This car is with a immobiliser from the factory. Should be with the fat key and a NFC-chip.
Fuse 5: check the light inside the glove box. Second the power antenna.
Later open the sockets on the towbar and check every wire carefully or remove the full wiring.
Light at engine bay may be on too. Not every 940 is with this, some are. The socket is already at the engine bay.
Good luck and don't think about a bigger alternator, Kay
mocambique-amazone is offline   Reply With Quote
The Following 2 Users Say Thank You to mocambique-amazone For This Useful Post:
Old Oct 27th, 2019, 20:01   #28
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Yesterday 21:57
Join Date: May 2012
Location: Lakenheath
Default

Quote:
Originally Posted by 940volvoman View Post
The rectifier is included in the voltage regulator (2 problems sorted in one here...) The rectifier being the diode that flattens the current curve.
Whoever told you that is one of the following :

1. Lying

2. Misinformed

3. Telling you that to get a sale (see 1 above)

4. Stupid

5. Knows nothing about autoelectrics and in particular, alternator construction and repair thereof.

6. WRONG!

7. Having a laugh! (The remark about one single diode flattening the current curve had me in stitches!)

8. ALL of the above!

There are 9 diodes in the rectifier, 6 rectify the AC into DC and the other three form a "trio" to feed into the voltage regulator. The only thing the voltage regulator is combined with is the brush box.

This is the rectifier :



This is the voltage regulator :



Also i bet you didn't check the condition of the slip-rings when you changed the regulator?



I've diagnosed and repaired thousands of these and reconditioned thousands more.

Now, if you can get the 0 120 number off the green Bosch label on the alternator, i can confirm exactly which one you've got and which rectifier it has. It's probably the one above but i deliberately haven't linked to any parts/part numbers because if i'm wrong, it won't take long before you're in the same boat again.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........

Last edited by Laird Scooby; Oct 27th, 2019 at 20:06. Reason: Typose - errr, typos even!
Laird Scooby is offline   Reply With Quote
The Following 4 Users Say Thank You to Laird Scooby For This Useful Post:
Old Oct 27th, 2019, 21:17   #29
940volvoman
Master Member
 

Last Online: Mar 25th, 2024 19:11
Join Date: Mar 2017
Location: Burgess Hill
Default

OK,Laird Scooby,that was based on information I gleened fromT' Internet.

My bad/ignorance. I bow to your superior knowledge.
In response to your earlier questions, I currently have a black Yuasa with lifetime guarantee .It is just one of a string of batteries of which Banner and Bosch are a part. All of which would have been checked for compatibility by registration.What type would you recommend?

The alternator number is 0123 500 005 HTH...

Now you can stop laughing

Last edited by 940volvoman; Oct 27th, 2019 at 21:53.
940volvoman is offline   Reply With Quote
The Following User Says Thank You to 940volvoman For This Useful Post:
Old Oct 27th, 2019, 22:12   #30
Laird Scooby
Premier Member
 
Laird Scooby's Avatar
 

Last Online: Yesterday 21:57
Join Date: May 2012
Location: Lakenheath
Default

This is the list of different parts that should fit that one in that case :

https://www.woodauto.com/bom/32855/BOSCH-0120465018

The rectifier is actually beefier than i described earlier and has twice as many diodes as i thought to handle the current - 14 as far as i can see!

The battery, is it a normal lead-acid battery or is it a "Calcium Technology", Silver Calcium" or similar? If the number is "YBX nnn" then if memory serves, it's a calcium one. Need to know the construction rather than the make.
Sadly the people that sell the batteries don't know about charging and the problems the silver-calcium coating presents instead of the more traditional lead-antimony coating on the plates. Both coatings are there to mitigate sulphation but the calcium needs a higher charging voltage.
Because of this, cross-referencing on the reg number doesn't always work.
__________________
Cheers
Dave

Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........
Laird Scooby is offline   Reply With Quote
The Following User Says Thank You to Laird Scooby 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 03:01.


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