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1998 s70 reverse jump polarity troubleshooting. Bad relays 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

Derbyrunner
Posts: 14
Joined: Wed Aug 17, 2016 6:26 am
Year and Model: 1998 S70
Location: Kentucky

Re: Ignition fuse keeps blowing.

Post by Derbyrunner »

I took out all the bigger fuses 50 amp and 60 amp. With key turned to on position the #6 60amp fuse labeled power to fuse box and aliment. Bootier fusib is sending the power to #10 15amp ignition fuse.
Derbyrunner
Posts: 14
Joined: Wed Aug 17, 2016 6:26 am
Year and Model: 1998 S70
Location: Kentucky

Re: Ignition fuse keeps blowing.

Post by Derbyrunner »

BEJinFbk wrote:That's the fuse that actually feeds the ignition switch itself.
From there it branches out to several things, including accessory
overload relays 105 and 106.
One way to deal with this is take a picture of the fuse box,
pull all of the other fuses and start putting them back one at
a time with the key on. Long way around, but it's a start.

This may help:
98 S-V70 Fuse Locations and Legends.pdf


UPDATE the beast is up and going again. The short was in the 106 relay and main engine relay or at least one of the two as I changed both. Went through about 4 boxes of 15 amp fuses but that's cheaper than other big ticketed items. Thanks to everyone for input! I really appreciate it!
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BEJinFbk
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Re: Ignition fuse keeps blowing.

Post by BEJinFbk »

Those relays usually have a spike protection diode on the coil legs.
The reverse polarity probably melted it into a nice short to ground...

Glad you got it running! ;)
'98 V70 R - Well Equipped for Life Up North... ;)
Derbyrunner
Posts: 14
Joined: Wed Aug 17, 2016 6:26 am
Year and Model: 1998 S70
Location: Kentucky

Re: Ignition fuse keeps blowing.

Post by Derbyrunner »

The long way around proved to be a tedious job but worked out. I went through about 4 boxes of 15 amp fuses to narrow it down to main engine relay and relay #104 I think. It's running again and I'm very appreciative of all the input
scot850
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Re: Ignition fuse keeps blowing.

Post by scot850 »

Well done for being persistent and seeing it through. Good input from all the guys who helped also!

Neil.
2000 V70 R - still being an endless PITA
2006 XC70
2003 Toyota 4Runner V8 Limited
2015 Kia Sportage EX-L
1993 850 GLT -Sold
1998 V70 XC - Sold
1997 Volvo 850 SE NA - Went to niece in California - Sold
2000 V70 SE NA - New project and test bed - Sold
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abscate
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Re: 1998 S70 reverse jump polarity troubleshooting. Bad relays

Post by abscate »

Changed thread title for search.
Thanks for sharing outcome as this might save someone a lot of fuses next time!
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m96ag
Posts: 171
Joined: Wed Jun 12, 2013 2:08 pm
Year and Model: 2000 V70XC
Location: USA

Re: Ignition fuse keeps blowing.

Post by m96ag »

Derbyrunner wrote:The long way around proved to be a tedious job but worked out. I went through about 4 boxes of 15 amp fuses to narrow it down to main engine relay and relay #104 I think. It's running again and I'm very appreciative of all the input
Tip for anyone reading this. If you're doing this kind of troubleshooting go and buy one of these circuit breakers and put it in place for testing to save a pile of fuses. https://www.amazon.com/Bussmann-BP-UCB- ... reaker+atc
2000 V70XC 160,000mi.
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erikv11
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Re: 1998 S70 reverse jump polarity troubleshooting. Bad relays

Post by erikv11 »

Somehow I missed this thread. First step (after replacing any blown fuses) is always to replace the three J relays, they are cheap and one or more of them will always be blown.
'95 854 T5-R, Motronic 4.4, 185k
'96 855 NA, 145k
'98 S70 NA, 220k (living out west)
'98 V70, T5 tune-injectors-turbo, LPT engine, 293k
'06 S60 R, 167k
'99 Camry V6 :shock: 130k
gone: '96 NA 850 210k, '98 NA V70 182k
jonl
Posts: 86
Joined: Thu Jan 07, 2010 5:54 am
Year and Model: V70XC, 2000
Location: Maryland

Re: 1998 S70 reverse jump polarity troubleshooting. Bad relays

Post by jonl »

Hi Derbyrunner,

I've a 2000 V70XC and did something similar to my car this morning. How did you know that your 106 and/or main engine relays were your problem?
Thanks a bunch,
Jon
2000 V70XC with 185k
cn90
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Re: 1998 S70 reverse jump polarity troubleshooting. Bad relays

Post by cn90 »

Jump the relay, if car runs, relay is bad.
Or get a few spare relays from junk yard for testing, make sure you label them which is which before swapping!
2004 V70 2.5T 100K+
2005 XC90 2.5T 110K+
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