Porsche Enthusiasts Club Forum

Hi all
A minor problem on My 1987 s4 manual. Today I decided to replace rear window demist switch with a spare bought on ebay after testing swapped back to original one.Now my door red guard lights and my door interior lights dont work on the delay mode ,the door lights work fine on permanent setting all other interior lights work boot etc. Just the delay all bulbs fine as are fuses could this be a duff relay? There is power to both the red door guard lights but the bulb will not light. HELP its doing my head in i like things to work
Thanks in anticipation Grahame

Hi Grahame the red door markers don't work on delay. They should be permanently lit whenever doors open as safety measure.

Are you also saying the footwell lights no longer light when a door opened? But the front, rear and hatch roof lights come on correctly and extinguish after delay when door closed?

Hi Stratfordshark
The rear hatch lights and the center roof light work fine and go out as soon as the doors are shut . The door red markers dont work at all now, and as you say did never have any delay. Its the door lights that dont work on the delay but do work when switched on permanent light. Hope this makes sense
thanks Grahame

Hmm you say roof lights go out as soon as doirs shut, but they should be on same delay as the (non-working) door lights.

If as you say there is 12V to marker lights but they don't light then can only be blown bulbs, but odds of simultaneous failure vanishingly low! Are you certain there is 12V to the "hot" sideof bulb, and a continuous ground to door frame?

Was all ok prior to replacing demist switch?

I would first try relacement fir interior light relay, since that includes the timer circuitry.

Hello stratfordshark
Yes they were all working fine before the rear hatch demist switch test but stupidly perhaps i did not disconnect the battery in swapping the switches over perhaps that caused a spike to the relay? When i bought the car non of the interior lights worked and i traced that to a broken wire on the door plunger switch and also corrosion to the red door warning light bulb b9 holders which incidentally you can buy on ebay.I reckon as you that the relay is at fault and shall look out again on ebay for a good second hand one .
two lessons learned here if it aint broke dont mess with it. and disconnect the battery every time you touch relays and swtches doh!
Thanks for your help cheers Grahame

Hi Grahame

We've all had that "if only I'd...." moment, but in this case I'm struggling to think of connection (no pun!) between messing around with pod switches and any problem with light delay/marker lights. The pod switch as you know plugs straight into wiring loom (female) so hard to think of how short might have occurred, let alone how that might create interior light problem.

Hope you getit sorted soon. Please post if relay at least fixed delay problem. The footwell lights are on same circuit as roof lights so it sounds more like those lights have failec (they literally melt inside).

I wonder if you had door open to work on demist switch, and the footwell lights just gave up ghost on the switched setting?

H all
Just sorted the problem,it was the interior light relay i took it apart and noticed a dodgy solder on one of the pin terminals resoldered it and its fixed and for free!
Now if the rest of the year goes like that it should be a good one !
Cheers and happy new year Grahame

Good work Grahame!