240 Reverse light out

ljk346

Hi, currently doing a hard wire job on my 1991 240 rear light clusters.
Testing all the lights after the job and found that i can't get the reverse lights to work
(only have 1 cluster in (right one) at the moment because i'm wiring the other one currently)

Tested the reverse bulb by plugging it into the blinker wire, works fine. So my side of the wires is ok.
Checked the fuses, all good. Internet vs service manual vs fuse panel is somewhat sketchy on which is the reverse light fuse (think its the bottom 2 for L and R), tested the rear lights, which lit up fine with the test light, but nothing in either reverse light fuse.

help pls

cheers

Major Ledfoot

Your car is a 1991, yes? According to this diagram, both reverse lights use fuse #6 for juice.

http://www.volvowiringdiagrams.com/volvo/240%20Wiring%20Diagrams/Volvo%20240%201991.pdf

Check the reverse lamp switch connector (C) and the reverse lamp switch itself (D), which are found in the locations shown in the diagram below (NOTE - that diagram indicates fuse #5, but it's apparently #6 on a 1991, and the wire colours are also different to the diagram below).

familyman

I'm unclear on the tests you're describing. But I assume by 'hard-wire' mean you've replaced the thin plastic circuit. (If not, check the lugs on the bulb side of the bulb holder are touching the circuit.

Another thing I was going I was going to say... is to test by putting the car in reverse (and ignition turned to dash ignition lights to on position) - then hold a multimeter across where the reverse bulb would connect. If no voltage is present, then as above check the fuse. I just spin them in place and they work again. But others say to actually remove, wire brush the ends with one of those cheap wire "toothbrushes" that usually come three in a pack. And do the same to the tabs they socket into (with the battery disconnected!). Also check the fuse isn't open circuit with a hairline crack, etc. with a multimeter, then reposition it into place.

From there you could check the reverse switch on the shifter is connecting/disconnecting.

Then (or first) test the wiring with a meter for continuity to the reverse switch.

ljk346

@bgpzfm142 yeah it's a 91
Thanks for the info and diagrams
Will attempt to find connector C and D tonight after work
@familyman yes you are correct in thinking I am removing that troublesome plastic circuit
Basically just put wires where the circuit went in the first place, with a ground jumping between all the bulbs and grounding in OEM position. Also put crimped spades where the original plastic wire holder thingo went. Easy disconnect
Not sure about the wire brush ends? Please explain?

Rob

I just did this job myself on the weekend.

I think you will find that you need to have the left light plugged in in order for the rh reverse light to work. the wire from the switch feeds into the plug on the lh light, through the circuit board and back out another wire that runs across to the rh reverse light. I just crimped them into the same join when i replaced the wiring.

Ex850R

Do you two have pix of the modification?
I was thinking of doing a mod myself last night when I checked and found a blown brake bulb in the 240.Someone does new boards but I want a better option.

Rob

It is quite easy, pull the light apart, pull the bulb carriers out, rip the board off. You need to use side cutters to trim each of the terminals down to a width where female spade terminals will slide on. Slip them on and wire it all up. Put the bulb carriers back in and done. It is not quite as pretty as the original setup but is super reliable.

Pics courtesy of Dave Barton

Ex850R

Thank you Rob.

familyman

What I meant with the wire brush... I've seen many people say it's common for the fuse holder to corrode. (I've never had this trouble with the few 240s I've owned, apart from a few fuses needing a spin with my finger. But I've seen where people swap the fuse block for another type, so they can use ditch the european-style fuses for the glass type.)

Anyway... Other people disconnect the battery, pull all fuses out, clean the terminals with a wire 'toothbrush', then reinstall the fuses. Some also smear conductive grease on the ends of the fuses to 'seal' it from the air and prevent future corrosion.

Places like $2/junk shops, supercheap auto, repco, etc. - most of them sell a clear plastic bubble pack containing 3 'toothbrushes' (about 1.5x the size of a normal toothbrush). The handles are are black plastic, and usually one has stainless steel bristles, one has black nylon bristles, and #3 is either brass or just a second black nylon.

Like this :-)

http://www.supercheapauto.com.au/Product/Stanley-Wire-Brush-Set-3-Piece/12583

ljk346

@Rob I have already completed a single tail light using this method as well as OEM wire colours matched, except I found my crimped connectors stuck out to far and bent the wires at weird angles. I resorted to soldering the wires directly to the terminal with some heat shrink. Works great so far, apart from that reverse light :P

Rob

I recommend this type

otherwise yes, soldering them on would work nicely.

I still reckon your problem will be the fact that the lh tail lamp is not fitted.

if you go to the lh tail lamp plug and crimp the 2 side by side black wires together the rh reverse light will come on.. I would bet on it.

ljk346

I'll try it out...

@Rob Success! When I join the two black wires together I get a reverse light. Not sure which is + and - because it doesn't work when I ground either wire to the body. What does this means for the wiring side of things?, as I used the same ground for all my bulbs before, so this is different? Or use a black wire as a ground instead of the body wire?
+1 Swedish point for you

Rob

No problem.

Don't confuse these two black wires with earths, despite being black they are not earth wires.

One wire comes in from the reverse switch and is the + supply to the LH reverse light, the other is the wire that goes across and supplies + to the RH light. All you need to do is crimp these together into the one terminal or crimp/solder them together per the diagram below (with or without the spade joints).

Which wire is which is not important at all.