IPD sale XeMODeX - Experts in Volvo Electronics Free shipping all USA - Experts in Brakes
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy anything with this and it helps MVS!

1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT Topic is solved

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

User avatar
wizechatmgr
Posts: 1344
Joined: Thu Jan 12, 2017 1:07 pm
Year and Model: 1999 V70 XC AWD 2.4T
Location: Albany, NY area
Has thanked: 23 times
Been thanked: 56 times
Contact:
United States of America
wizechatmgr

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by wizechatmgr » Fri Sep 08, 2017 9:05 pm

Received the PDF, thank you.

I was looking at it and still don't like the OEM solution - even more so now that I see what they did. This particular part shouldn't move much so their usage of the ~4 smaller gauge wires really isn't a great idea. I'm thinking of removing the ends and replacing it with an 8 Gauge cable which should be good for ~50+ amps and potentially allow additional current with little to no measurable drop. My belief is this was designed this way in order to allow flex - flex that shouldn't occur. I plan on bypassing the existing loom and adding some loom of my own. I just have to find some time to do this, my crimpers, a cold chisel, a hammer and my ~250+W soldering gun and my rosin paste.

This likely won't happen until next week. Rumor has it next week will be dry, so I may make a little workup for it. They're running $60-80 for that wire OEM. I think it is a good part, but I think mine will last longer and be easier to inspect.

Rumor has it the part number of the actual wire is Volvo 8628771. (Thanks @Novaman83)

Currently the vehicle only has this issue on right turns... I'm serious, and not every right turn, just the ones where you don't expect it to cut out... I suppose I could just make all left turns. I now have a spare ignition switch to add to the Albany Volvo club experience.

If this doesn't do it, my next thought is the battery. Perhaps I have a cell with a broken tie to the post that intermittently loses connectivity. I figure that even if the other circuit on the other end of the terminal - the line that goes to the starter and then on to the alternator is bad, then it "should" have stayed running unless it was grounding out. I believe I would have smelled the grounding out (ozone/arcing) in order to create a short sufficient to cut the car off... Battery needs to be checked for winter - so if this doesn't do it, I may replace it just so I know the last time the battery was replaced.

Off topic: Does anyone know which Optima Red top fits our car? They have no listing and I'd rather not go to a local dealer in order to play "does it fit" for an hour. I love the Optima batteries.
Wisdom requires knowledge as a prerequisite, but knowledge can be developed due to a lack of wisdom.
In order to learn how to fix something, you must first learn how to break it.
1999 V70 XC AWD - ~187k miles

User avatar
BEJinFbk
Posts: 3697
Joined: Sat Jan 05, 2008 10:32 pm
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 23 times
Been thanked: 44 times
United States of America
BEJinFbk

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by BEJinFbk » Fri Sep 08, 2017 11:09 pm

I remember Basic...
'98 V70 R - Well Equipped for Life Up North... ;)

User avatar
wizechatmgr
Posts: 1344
Joined: Thu Jan 12, 2017 1:07 pm
Year and Model: 1999 V70 XC AWD 2.4T
Location: Albany, NY area
Has thanked: 23 times
Been thanked: 56 times
Contact:
United States of America
wizechatmgr

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT  Topic is solved

Post by wizechatmgr » Sat Sep 09, 2017 4:33 pm

Embarrassing info ahead...

Car died on road to work earlier. Cut out, restarted and cut out about 100 yards away - now it refuses to restart, no gauges, nothing. This is actually good news as intermittent issues SUCK, I'd much rather she be on the side of the road dead as it is easier to troubleshoot... Opened hood, smelled a small hint of ozone toward the right. Checked and sadly confirmed that the little B+ wire from Main fuse box was loose on the B+ terminal that connects to the battery post. Tightened it down, no issue, immediately fires up.

In my haste to troubleshoot this issue I didn't check the basics as I should have... I had checked the terminal to the battery post, but not the auxiliary that heads to the main fusebox *face palm*

Time to buy the battery hold down clamp - I am willing to bet that since the battery slides slightly to the left side as I make a right hand turn, this would explain the seemingly random cut outs as that cable proceeded to loosen. Will also install a split-ring lock washer of correct size assuming she doesn't have the issue for another couple of days.
Wisdom requires knowledge as a prerequisite, but knowledge can be developed due to a lack of wisdom.
In order to learn how to fix something, you must first learn how to break it.
1999 V70 XC AWD - ~187k miles

User avatar
abscate
MVS Moderator
Posts: 20514
Joined: Sun Feb 17, 2013 5:54 pm
Year and Model: 99T5 ,99S70,2005V70
Location: NYC, ALBANY NY
Has thanked: 287 times
Been thanked: 904 times
Trinidad & Tobago
abscate

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by abscate » Sun Sep 10, 2017 1:40 am

You have dulled your Occam's razor on my thick skull.....remember the light bulbs?



:-)
Empty Nester
A Captain in a Sea of Estrogen
1999-V70-T5M56 2005-V70-M56 1999-S70 VW T4 BMW
Link to Maintenance record thread
Link To Volvo Glossary

User avatar
wizechatmgr
Posts: 1344
Joined: Thu Jan 12, 2017 1:07 pm
Year and Model: 1999 V70 XC AWD 2.4T
Location: Albany, NY area
Has thanked: 23 times
Been thanked: 56 times
Contact:
United States of America
wizechatmgr

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by wizechatmgr » Sun Sep 10, 2017 3:41 am

We all have those moments. I now have an ignition switch that now should have at least a good ~18 years of life left and a spare...
Wisdom requires knowledge as a prerequisite, but knowledge can be developed due to a lack of wisdom.
In order to learn how to fix something, you must first learn how to break it.
1999 V70 XC AWD - ~187k miles

novaman83
Posts: 20
Joined: Sun Jan 30, 2011 3:04 pm
Year and Model: 1998 V70
Location: Alexandria, VA
Has thanked: 0
Been thanked: 0
United States of America
novaman83

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by novaman83 » Sun Sep 10, 2017 10:46 am

Replaced cable yesterday Per TSB instructions. Easy to follow. But note: Old cable i removed by cutting off end at battery and puling cable out from the TOP of the fuse box. The new cable is installed by passing the battery end DOWN through the top of the fuse box and through the bottom grommet. To do this, you must straighten the terminal that attaches to the battery first. The grommet at the bottom has great stretchability.


BTW, nut on B+ cable was only finger tight. My theory is heat/cool cycles loosened the nut and that led to arching which damaged the wiring by overheating. B+ cable was replaced in 2013 by a guy I really trust. I am 99% sure, that nut was tight when he installed the new cable in 2013.
Check every 6,000 miles or so to be sure nut is tight and use dielectric grease on both ends.
Attachments
b+ image.jpg
b+ image.jpg (1.25 MiB) Viewed 942 times

novaman83
Posts: 20
Joined: Sun Jan 30, 2011 3:04 pm
Year and Model: 1998 V70
Location: Alexandria, VA
Has thanked: 0
Been thanked: 0
United States of America
novaman83

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by novaman83 » Sun Sep 10, 2017 10:57 am

Once you read the TSB it is obvious you can fabricate a new cable for a few bucks and run it the same way the OEM cable was run. I had an OEM cable on hand so I used it. I plan to keep an eye on mine...at the first sign of over heating,I will run a "helper" cable. So far, even with lights and AC, the terminal in the fuse box runs cool.
But, periodic checks on nut tightness at terminal will save the day!

From another poster:
Supplies from NAPA:
You would need about 42" of 6 AWG cable of good quality (fine wires). A good alternative will be 4X lengths of 14 gauge (fine wires). You will gain in flexibility during the installation in the fuse box. There is very little space.

Terminals;

Napa 784581, 1 X but sold in 10 units per box. Around 4$
Standard BP 303, 1 X for .75 cents

novaman83
Posts: 20
Joined: Sun Jan 30, 2011 3:04 pm
Year and Model: 1998 V70
Location: Alexandria, VA
Has thanked: 0
Been thanked: 0
United States of America
novaman83

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by novaman83 » Sun Sep 10, 2017 1:57 pm

Just found out I could post the PDF
Attachments
B+ cable Volvo 1998 to 2000.pdf
(1.66 MiB) Downloaded 50 times

User avatar
wizechatmgr
Posts: 1344
Joined: Thu Jan 12, 2017 1:07 pm
Year and Model: 1999 V70 XC AWD 2.4T
Location: Albany, NY area
Has thanked: 23 times
Been thanked: 56 times
Contact:
United States of America
wizechatmgr

Re: 1999 V790 XC AWD - Removing B+ cable from main fuse box - OR NOT

Post by wizechatmgr » Sun Sep 10, 2017 5:33 pm

Good stuff!
Wisdom requires knowledge as a prerequisite, but knowledge can be developed due to a lack of wisdom.
In order to learn how to fix something, you must first learn how to break it.
1999 V70 XC AWD - ~187k miles

Post Reply
  • Similar Topics
    Replies
    Views
    Last post