1991 Volvo 240...bottom of fuse rail, 8 Amp fuse blew..replaced..blew again...pass blinker operates fine...brake lights operates fine...running lights, in-op...keeps blowing the bottom 8 Amp fuse! New bulbs..everything functions except running lights on passenger side...drivers side, nice and bright!! What am I missing?? Any clues will be greatly appreciated

 

The 2 bottom fuses for left and right parking lights - from memory, the tag lights are on one of those fuses and the dash lights are on the other.
What does not work when the fuse blows - tag or dash lights?

 

TY for the reply...Tag lights working. The fuse that's blown includes the dash lights.. recap,right running lights out..dash out...taglights operating fine,nice and bright Ja

 

Actually a very important piece of info...fuse blows when headlights are turned on!

 

FYI the headlights function properly, high and low beams nice and bright I should have included that to you, ja

 

guessing bad ground increasing the draw by providing an additional "resistor" in the circuit?

.. but that's wrong I think..., it would increase the circuit resistance , decreasing amps being drawn..

If you can check the amp draw through the fuse, and unplug the light bulbs is it still drawing juice? short to ground somewhere?

another load that you didn't know about in that circuit, IE through the same fuse?
knowing the amp draw is helpful but is your meter capable of this? the meter might have a limit on how many amps it can measure in direct connection, a clamp meter is another way, maybe harder to hurt the meter.. be careful.

 

So - if it's still blowing a left or right parking fuse (one if the two bottom fuses) - simply unplug the output wires one at a time at the fusebox to determine which wire the short is on. Yes sometimes you have to snip wires leaving enough room for a butt splicer once you find where that wire is shorting to ground. Or - do all 3 console light bulbs work? light bar over rocker switches, and fan sw and temp slider? Those bulb holders fall out once the plastic gets brittle from old age - and the connectors to the bulb holders are not insulated and can easily touch something metal back there. - How about the shift indicator bulb, those wires get bent every time the shifter moves, or the one over the rear ashtray?

 

I do so much appreciate the advice...I'd dropped out of the repair...lost my mother, so I'll be back on diagnosis with your great advice..so very appreciated...ty..ja

 

Sorry for your loss. The Volvo will be there when you're ready.