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850 sedan trunk lock testing question.

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

Teddy1975
Posts: 246
Joined: Wed Jan 06, 2016 11:57 am
Year and Model: 850 1996
Location: Denmark
Has thanked: 0
Been thanked: 7 times
Denmark
Teddy1975

Re: 850 sedan trunk lock testing question.

Post by Teddy1975 » Tue Jul 12, 2016 2:14 am

Less than one (1) amp is needed as the motor is really small. If you have a small power supply, then use this instead of a car battery. If you only have a car battery, make sure to put a small fuse (5A or smaller) on the live wire to prevent damage done to the wire harness and/or central locking relay.
fused.png
fused.png (6.17 KiB) Viewed 403 times
Caution: Do NOT put any voltage on the wires while they are plugged into the harness. Terminal 6 and 7 are short circuited when plugged in and the central locking system isn't operating the door locks. This is intended.

To test it, use this table:
Action+12v (live)Ground (negative)
LockTerm #6, YEL-BRNTerm #7, YEL
UnlockTerm #7, YELTerm #6, YEL-BRN
Don't keep power on the motor for a longer period than a second or so. There is a small risk of overheating the wiring inside the motor, which will render it useless.

If you pay attention to the cautions, this is quite easy to do with no risks involved.
Current: 850 2.0L N/A, 4 door 1996 manual
Previous: 740 2.3L N/A, 5 door 1992 manual, and S70 2.5T 1999 manual

scot850
Posts: 5762
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 9 times
Been thanked: 187 times
Canada
scot850

Re: 850 sedan trunk lock testing question.

Post by scot850 » Tue Jul 12, 2016 8:26 am

I will use my 2A trickle charger and just touch the pin to see if there is any movement. Warning is noted!

Thanks again.

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

Teddy1975
Posts: 246
Joined: Wed Jan 06, 2016 11:57 am
Year and Model: 850 1996
Location: Denmark
Has thanked: 0
Been thanked: 7 times
Denmark
Teddy1975

Re: 850 sedan trunk lock testing question.

Post by Teddy1975 » Thu Jul 14, 2016 8:54 pm

Hi Neil.

Did you have any luck with the lock? :D
Current: 850 2.0L N/A, 4 door 1996 manual
Previous: 740 2.3L N/A, 5 door 1992 manual, and S70 2.5T 1999 manual

scot850
Posts: 5762
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 9 times
Been thanked: 187 times
Canada
scot850

Re: 850 sedan trunk lock testing question.

Post by scot850 » Thu Jul 14, 2016 11:09 pm

No, none at all, and neither with the fuel flap lock. Both appear dead. I have pulled a bunch of fuel flap locks at a junkyard and plan to try them tomorrow, along with a couple of trunk locks (most of the 96- Volvos were wagons so not much choice). I'm hoping that one of each will be good when plugged in so I can verify the problem is the electric motors and not the wiring or something else.

I plan to do that tomorrow and I'll let you know how that goes.

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

scot850
Posts: 5762
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 9 times
Been thanked: 187 times
Canada
scot850

Re: 850 sedan trunk lock testing question.

Post by scot850 » Fri Jul 15, 2016 5:39 pm

Although I can't be 100% sure yet, I may have found the source of the problem. After trying 2 more motors with no luck (my view is surely 3 motors can't all be bad) was to check the wiring. I removed the cover that runs up the trunk hinge and cut the plastic (fibreglass?) sheathing (and it cut my finger, bugger that stuff is sharp!!), and no obvious broken wires at the point where the wires leave the plastic cover. I pulled the back mesh sheathing back lower and found 3 broken wires loose in my hand. Just what I love, repairing hard to access wiring with sausage fingers! So I will have to make up a short pig tail and solder it in.

The fuel tank lock was just a (an expensive) dud motor. I pulled 7 ($5 CDN each rather than $135 CDN from the dealer) and 4/7 were good. 1 of the 7 was from a S70 and looks physically the same, but when connected it un-locks then re-locks itself. Weird. Hoping to see if they were also compatible. It may of course be the motor itself, but I don't plan to pull the 'R' apart to prove it! Maybe P80 fuel locks work differently?

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

scot850
Posts: 5762
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 9 times
Been thanked: 187 times
Canada
scot850

Re: 850 sedan trunk lock testing question.

Post by scot850 » Sun Jul 17, 2016 10:57 pm

Was busy this weekend and so only had a half hour tonight to look at the wiring. I just used wiring marrettes to temporarily re-connect the 4(!) broken wires to see what happens. Good news is the lock assembly works fine as did the 2 spares I got from PnP. Not sure about keeping the spares as I will not have a need for them, but torn as I know if I return them good parts will likely just get junked.

I'll have to take a run back to PnP and look at pulling the trunk harness from a car to give the correct wiring colors to fix the loom. Hopefully good for another 20 years!

It would appear that using my trickle charger to try to test the motor on the trunk latch didn't work. May have try my regular charger on 2A to see if it is how the trickle charger works that it won't make the motor work even when just trying to 'dab' the connections.

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

Teddy1975
Posts: 246
Joined: Wed Jan 06, 2016 11:57 am
Year and Model: 850 1996
Location: Denmark
Has thanked: 0
Been thanked: 7 times
Denmark
Teddy1975

Re: 850 sedan trunk lock testing question.

Post by Teddy1975 » Wed Jul 20, 2016 1:35 pm

Or use the car battery. Just make sure to have a 2A or 5A fuse inline.

Battery chargers, especially the "intelligent" ones can fluctuate quite a lot in both power and voltage and need the bigger load of a battery to really work.

I use a small variable lab powersupply that has an output from 0-30 volts DC at max 3A for testing stuff like electro motors, LEDs, bulbs and other electronics.
Current: 850 2.0L N/A, 4 door 1996 manual
Previous: 740 2.3L N/A, 5 door 1992 manual, and S70 2.5T 1999 manual

scot850
Posts: 5762
Joined: Mon Apr 05, 2010 2:46 pm
Year and Model: 2000 V70 R
Location: Calgary, Alberta, Canada
Has thanked: 9 times
Been thanked: 187 times
Canada
scot850

Re: 850 sedan trunk lock testing question.

Post by scot850 » Wed Jul 20, 2016 7:45 pm

Having a lab variable voltage supply would be handy! Either way I bought a bunch of used parts from Pick and Pull and found the fuel flap motor was junk, and the wiring harness for the trunk lock had 4 broken wires at the hinge. I temporarily reconnected them and the motor (and the 2 spares I pulled) were all fine. Now have to repair the harness.

Thanks for the input and help. Really appreciated.

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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