1984 fog light relay?!

james944 · Jul 10, 2013

I've been tearing my hair out with this. Looking at the wiring diagram in my Haynes Manual there is clearly a fog light relay in the 1984 page 1 of 5 wiring diagram. I dont know if any of you have a manual you could look. I've taken a picture of the page and circled it (page 203 bottom middle of the page) but I don't know if I'll be able to post it because of the size!

Failed my MOT this week on rear fogs but can't seem to work out what's gone wrong. Anyone have any ideas.

Thanks, James.

924nutter · Jul 10, 2013

First of all pull the fuses for the low beam, because the headlights need to be on low beam to energise the F/L relay, and this will give you time to trace out the wiring and supply voltage before you flatten the battery. If any rear lamps work then the earth is ok so it will be a supply problem. In my post about a dme relay for a 1982 944, there is a link to the online 944 owners handbook which show the location of the relays on virtual page 57/58

924nutter · Jul 10, 2013

James I have just checked the manual and it lists addition fog lights as an option, probably because of U S spec as it includes side markers. All I can suggest is to check to see if you have a relay in the top row fifth socket from the left, or on the bottom row first left as there are no relays in these sockets in the owners manual or possibly second left although this is designated additional headlights.

james944 · Jul 11, 2013

Hi John. Well every other bulb at the rear of the car lights up (side lights, turn signals, brakes and reverse lights) but not the fogs at all. So I guess that eliminates a bad earth/ground, right? Save me wasting time cleaning them up!

Changed the DME relay today and fiddled with fuses and relay box but still nothing. Noticed when I dismantled the switch on the centre console above the heating controls that it doesn't light up when you switch it on. This would mean I'm not getting power to the switch! I need an auto electrician!!

Also after fiddling today 1 of my reverse lights now doesn't work but the other does. Bulb is fine because I teated it in the turn signal slot. What is happening to my electrics?! Go away wiring gremlin!!

Chrishazle · Jul 11, 2013

Clown at Halfords autocentre failed my 968 cab last year for non-working rear fog lights - had very red face when I told him "It's a Porsche, you have to have certain front lights on before the rear fogs will operate, they're actually working fine, please change my fail cert for a pass cert!!". Can't remember exactly which front lights have to be on - sides, dipped heads or front fogs (which themselves need sidelights on to operate IIRC, guess who doesn't take his car out in fog!).