1998 v70 2.4L Jumper Cigar Lighter Fuse to Batt?

Post by **MrAl** » 20 Apr 2015, 00:05

Hi there,

A fuse in this car is for the cigarette lighter in the front. The fuse is under the hood in the 'fuse box'.

Now the problem is that the cigarette lighter plug turns off when the key is off, and i need it to stay on when the key is off, and even when the car is starting. This is mostly because i like to monitor the battery voltage when the car is starting because that is one of the best tests for battery condition which is easy to hook up because the meter just connects directly to the battery and there you go.

So what i propose to do is first pull the fuse, then jumper the cigar lighter tab to a new fuse holder with fuse, then that to the battery positive terminal. That will keep the lighter jack live even when the car is turned off, and still be protected with the proper fuse (15 amps or less).

I did this on my last car but in that one i ran separate wires. The real question here is will the computer get weird'd out and go nuts if this is done? (ha ha)

Thanks.

Blockpartie · Post by **Blockpartie** » 20 Apr 2015, 05:18

Just use the accessory plug under the dashboard. Provides you with every connection needed (+, -, constant +, highbeams, reverse) and you only have to buy wires and pins.
Fused for 30 amps.

Post by **erikv11** » 20 Apr 2015, 09:43

Take a look at the owner's manual for some basic information about the accessories connector (http://www.volvoclubthailand.com/man/pd ... l_1998.pdf page 159), pin number 1 is constant power and apparently rated for 20 amps (Blockpartie may know better though about the amperage).

Post by **MrAl** » 21 Apr 2015, 03:34

Hi,

Thanks to Blockpartie and Erik for that interesting information.

Thanks also for pointing to the car manual, i didn even know they had a pdf manual.

I didnt know there was a connector just for extra added stuff. That's nice really. I could probably use that then.

Any idea what kind of connector it is, like Molex or something?

Blockpartie · Post by **Blockpartie** » 21 Apr 2015, 06:03

You can get the owners manual for your car straight from Volvos website as well. They have a .pdf or .html based version. Pin out will be explained.

They don't explain the accessory plug in every owners manual, for some model years it isn't listed but it will be there. Big yellow plug clipped to a wiring distribution box. Volvo was nice enough to include a connector that fits so you only need pins and wiring.
Pins are ISO automotive standard pins. There is a choice of two sizes depending on power demands. Under no circumstances should you use cheap cables or solder the pins to cables - crimp them.
Constant power is rated for a 20A load and thus has a thick enough cable to support this. The whole circuit (constant, switched power and so on) is protected by a 30A fuse.

Post by **MrAl** » 23 Apr 2015, 04:03

Hello again,

That's very interesting, but one small question...

Why do you say that you should not solder the wires to your added connector (i assume this new connector will plug into the one that is already there)?
Is there a part number available for the mating connector (the one we would add that goes to our added accessory)?

My meter (my accessory) only draws less than 1ma so 20amps should be much much more than enough