Hot Wires for Dash Lamps and Parking Lamps

[Dandi54]

Hi Gents,

So happy to find this forum. I look forward to meeting as many of you as possible.

I currently have a sticky problem which recently arose after I replaced the throttle cable in my 91 240. I should note that the PO had replaced the OEM fuse panel with 3 nice, neat and new fuse boxes with modern fuses. Looks great and now resides under the dash.

However, after I worked on the cable I found that my dash lights and all parking lamps were inoperable. When I re-visited the area where I had been working I found a double white wire dangling from under the dash. Without a proper wire diagram, I assumed it might be related to the inoperative circuit so I found a spare lug on one of the fuses and connected these whites to it.

This spare terminal had white wires on the other side of the fuse so it made sense to me. And once connected, all of my lights came back on!! A good day!!

Except for the fact that these white wires quickly began to heat up and were almost too hot to touch so I disconnected the circuit and just thought for a while. I then tested them for voltage and found that when the HL switch was in the 2nd position (parking lamps and dash lights on), I had about 13.5 volts and then when I moved the switch to the 3rd position (HL's on in addition to the others) I only had about 12.5 volts. I should mention that my headlights always worked fine throughout this.

So I'm now wondering what else I might have disrupted during my throttle cable repair which might cause these wires to heat up like this or is this condition somehow unrelated OR could it be normal? The latter would scare me and I assume it's not the case anyway.

Obviously seeking some thoughts and/or direction. I'm not a great electrics guy although I've managed my way around MGB's for about 40 years so I do own a VOM!!

Thanks in advance, Gentlemen.

Dan

[Stephen Edwin]

The situation raises various thoughts. Including where are the replacement fuse boards that a connection could be dislodged. Throttle cable on right, fuse boards on left?

But to the problem in issue, my thoughts while the experts are awaited.

It must be that a wire is carrying more current than its intended current capacity and therefore becoming hot. What happens if you run a definitely adequate wire with an inline blade fuse holder to a good power source, say the little junction box near the battery, and connect to that?

Can you contact the previous owner and ask about a list of which fuses serve which circuits?

Can you deduce anything from the list of fuses on the inside of the cover of the original fuse board?



It would b interesting to know more about that upgrade to modern fuse boards. That original fuse board is a reliability issue. There have been some upgrades reported or hinted at in the forum.


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[Dandi54]

Hi!! I'm afraid the previous owner has dropped out of sight.

He was an avid Volvo guy and handed me 6,000.00 worth of receipts for parts and some labor over the past years upon my purchase so I know he was very involved in the car but, yes.....here I am without his assistance.

Your idea re running a heavy wire is something I was thinking about. Just can't envision the potential points between which to run it.

Dan

[Dandi54]

The replacement boards are directly under the steering wheel in back of the knee panel. There are 3 and they have about 5 fuses each. Admittedly, not very near the throttle cable work area, but I do think I knocked the wire off the spade terminal when removing the knee bolster somehow. It's always possible that it was off already but that begs the question as to how the lights were working without it connected to something.

Dan

[Dandi54]

And here's a shot of the box with the open terminal. It is the only one placed upside down and has a few white wires on the back.

[Stephen Edwin]

Hello.

If I understand correctly, you have a wire that feeds those lights, because when you connect it to the fuseboard those lights work?

I would run an adequate wire and inline fuse holder from that wire instead of connecting it to the fuse board. Take it to a good known power source. Almost ultimately, there is a little junction box near the battery. That should I hope keep things OK while you get to the bottom of the situation and connect things as they should be connected.

Is thee anywhere a list of which of the fuses serve what circuits? Does the original Volvo list help? On the inside of the original fuse board cover.

This could be an "early warning" to work out a list, in case of future problems.