Volvo 131 relay question

superspod · Jul 19th, 2021, 09:56

Hi all, I have a 1969 b20 131, and upon trying to trouble shoot an issue with the electrics associated with the top bullet fuse (and having cleaned the fuse box, connections, replaced fuses etc to no avail) I noticed my round relay the SR 803 unit has only got a brown wire and a grey wire plugged in and an empty spade terminal on the bottom.
Could this potentially be the cause of my electrical gremlins? I've tried looking at wiring diagrams to not much luck. If it is the cause, how can I resolve it?
Thank you so much in advance!

Derek UK · Jul 19th, 2021, 10:45

Symptoms? What is happening?

superspod · Jul 19th, 2021, 10:48

Basically nothing on the top fuse system system is working- no brake lights, no wipers, no interior lights, etc. from my research it looks like the missing wire is meant to go to the reversing light switch on the gearbox so i will go check that in a bit!

Ron Kwas · Jul 19th, 2021, 12:15

Ss;

"nothing on the top fuse system system is working- no brake lights, no wipers, no interior lights," The only load mentioned which is actually powered by Fuse 1 is Wipers. Brake Lights are powered from Fuse 2, (both are Ignition Power) and Interior Lights Fuse 4 (Battery Power).

Relay with Brown wire is for Reversing Light, but it should not have an unused terminal.

See also: https://www.sw-em.com/Fuses,%20Alloc...g.htm#122_(12V)

Good Hunting!

superspod · Jul 19th, 2021, 12:32

So update!
Definitely the wire heading to the reversing light switch missing! I suspect this is responsible for at least For the reverse lamp working but maybe the wipers, the washer bottle, and the brake lights not working as well at any point (I've been going off the little card in the fuse box for what is responsible for what)? Hopefully I will be able to find a cable to test this hypothesis soon!
Thank you again for all the help.

simonvolvo · Jul 19th, 2021, 15:35

Quote:

Originally Posted by superspod

So update!
Definitely the wire heading to the reversing light switch missing!

The wire (colour code: black) from relay to reversing light switch on the gearbox is not bound up with the rest of the wiring loom. That explains why it easily gets lost/forgotten about “in the heat of battle” (when doing a major job that involves e.g. dropping and re-fitting the engine + gearbox).

Easy enough to make up a new one if it has indeed gone missing.

Derek UK · Jul 19th, 2021, 18:42

Have you got 12v at either side of the top fuse?

HRA · Aug 3rd, 2021, 18:24

Would I be right in thinking that the top fuse is the short fat one? I had one that looked fine but only worked intermittently. The "fuse" bit that "blows" looked ok but there was a dry solder-joint between it and one of the end-caps. Every now and then the gremlins would strike - the car would drop out of overdrive, the radio would go silent and half a mile later the engine would stall because the after-market fuel-pump had stopped. When checking the fuses at the roadside I'd give each one a twiddle and that was enough to remake contact. I could re-start the car and be on my way without ever knowing what the problem had been.

It was only when I got another short fat fuse that I swapped them and took a close look at the original. It's probably still sitting in my desk drawer waiting for me to re-solder it!

Ron Kwas · Aug 3rd, 2021, 19:44

HRA;

Top Fuse 1 is indeed a 7 X 17mm (GBF) 25A shorty. You should check your owners manual for good additional info, but might want to make up the little fuse/load identifier card which resided in each FuseBlock upon delivery. See: https://www.sw-em.com/Fuses,%20Alloc....htm#122_(12V))

...and if you've had intermittent function, I first recommend cleaning all fuse-ends and FB clips to shiny metal, then reinstalling them with a dab of ACZP. See: https://www.sw-em.com/anti_corrosive_paste.htm

7 X 17mm 25A shorty fuses are available...unless you're located on a Jupiter outpost where access and availability might be an issue, repairing fuses is not absolutely necessary...

Also, IF F1 or associated connections open, the AMP Indicator would come ON.

Cheers

Derek UK · Aug 3rd, 2021, 21:46

If you keep giving the top fuse a twiddle it can cut the pointed ends off completely. By luck it can still make contact but worth a very close look.
You can make up a 25 amp blade fuse as a permanent fix or as an emergency add on for your tool box. See Ron's page.

Jul 19th, 2021, 12:15	#4
Ron Kwas Premier Member Last Online: Today 09:06 Join Date: Jul 2007 Location: Connecticut, USA	Ss; "nothing on the top fuse system system is working- no brake lights, no wipers, no interior lights," The only load mentioned which is actually powered by Fuse 1 is Wipers. Brake Lights are powered from Fuse 2, (both are Ignition Power) and Interior Lights Fuse 4 (Battery Power). Relay with Brown wire is for Reversing Light, but it should not have an unused terminal. See also: https://www.sw-em.com/Fuses,%20Alloc...g.htm#122_(12V) Good Hunting! Last edited by Ron Kwas; Jul 19th, 2021 at 12:22.

Aug 3rd, 2021, 19:44	#9
Ron Kwas Premier Member Last Online: Today 09:06 Join Date: Jul 2007 Location: Connecticut, USA	HRA; Top Fuse 1 is indeed a 7 X 17mm (GBF) 25A shorty. You should check your owners manual for good additional info, but might want to make up the little fuse/load identifier card which resided in each FuseBlock upon delivery. See: https://www.sw-em.com/Fuses,%20Alloc....htm#122_(12V)) ...and if you've had intermittent function, I first recommend cleaning all fuse-ends and FB clips to shiny metal, then reinstalling them with a dab of ACZP. See: https://www.sw-em.com/anti_corrosive_paste.htm 7 X 17mm 25A shorty fuses are available...unless you're located on a Jupiter outpost where access and availability might be an issue, repairing fuses is not absolutely necessary... Also, IF F1 or associated connections open, the AMP Indicator would come ON. Cheers Last edited by Ron Kwas; Aug 3rd, 2021 at 22:15.

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Jul 19th, 2021, 09:56	#1
superspod Member Last Online: Today 11:33 Join Date: Aug 2012 Location: gloucs	Volvo 131 relay question Hi all, I have a 1969 b20 131, and upon trying to trouble shoot an issue with the electrics associated with the top bullet fuse (and having cleaned the fuse box, connections, replaced fuses etc to no avail) I noticed my round relay the SR 803 unit has only got a brown wire and a grey wire plugged in and an empty spade terminal on the bottom. Could this potentially be the cause of my electrical gremlins? I've tried looking at wiring diagrams to not much luck. If it is the cause, how can I resolve it? Thank you so much in advance!

Jul 19th, 2021, 10:45	#2
Derek UK VOC Member Last Online: Today 15:32 Join Date: Jul 2006 Location: Chatham	Symptoms? What is happening?

Jul 19th, 2021, 10:48	#3
superspod Member Last Online: Today 11:33 Join Date: Aug 2012 Location: gloucs	Basically nothing on the top fuse system system is working- no brake lights, no wipers, no interior lights, etc. from my research it looks like the missing wire is meant to go to the reversing light switch on the gearbox so i will go check that in a bit!

Jul 19th, 2021, 12:32	#5
superspod Member Last Online: Today 11:33 Join Date: Aug 2012 Location: gloucs	So update! Definitely the wire heading to the reversing light switch missing! I suspect this is responsible for at least For the reverse lamp working but maybe the wipers, the washer bottle, and the brake lights not working as well at any point (I've been going off the little card in the fuse box for what is responsible for what)? Hopefully I will be able to find a cable to test this hypothesis soon! Thank you again for all the help.

Jul 19th, 2021, 18:42	#7
Derek UK VOC Member Last Online: Today 15:32 Join Date: Jul 2006 Location: Chatham	Have you got 12v at either side of the top fuse?

Aug 3rd, 2021, 18:24	#8
HRA Junior Member Last Online: Mar 28th, 2024 16:36 Join Date: Aug 2018 Location: Surrey	Would I be right in thinking that the top fuse is the short fat one? I had one that looked fine but only worked intermittently. The "fuse" bit that "blows" looked ok but there was a dry solder-joint between it and one of the end-caps. Every now and then the gremlins would strike - the car would drop out of overdrive, the radio would go silent and half a mile later the engine would stall because the after-market fuel-pump had stopped. When checking the fuses at the roadside I'd give each one a twiddle and that was enough to remake contact. I could re-start the car and be on my way without ever knowing what the problem had been. It was only when I got another short fat fuse that I swapped them and took a close look at the original. It's probably still sitting in my desk drawer waiting for me to re-solder it!

Aug 3rd, 2021, 21:46	#10
Derek UK VOC Member Last Online: Today 15:32 Join Date: Jul 2006 Location: Chatham	If you keep giving the top fuse a twiddle it can cut the pointed ends off completely. By luck it can still make contact but worth a very close look. You can make up a 25 amp blade fuse as a permanent fix or as an emergency add on for your tool box. See Ron's page.

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