osugasman

Worked when I got the car last Spring. Have since replaced the standard headlights with Tore's upgraded LED kit (so I was monkeying around in the front of the car) and also replaced the stock Becker with a Kenwood blue tooth unit (so I was also monkeying around right under the switch).

No fog lights. When I have the headlights on and pull on the fog light switch, the fog light switch lights up green but no voltage readout at the adapter plug for the fog light unit in the front of the car.

It clearly is a problem back inside the cabin, but before I start ripping out the new kenwood to troubleshoot the wiring by the switch, I have a question. Why would the switch itself light up if the wiring around the switch was disconnected? Should I be looking somewhere else?

--Brian

Garth S

Pull relay #31 and,
a) quick swap it with another 'grey' 4-pin relay ( eg horn) - gives a yea/nay on the relay once the key is turned to run & fogs switched on

b) if no go, stick a jumper in on the fog power supply side of the relay ( pin 30 to 87 of relay = pin 3 to pin 5 on the CE panel ... turn on key to run position .... that provides switched +12V directly to the fogs.

If they light up, fogs are OK, and the problem lies on the trigger side of the relay ( pins 85 to 86 .... which is what the dash switch energizes to close the relay - which is analogous to sticking in the jumper above).

This should pinpoint the issue ...

e9stibi

+2 on the relay.

osugasman

Garth,

Thanks!! Will try that later tonight.

--Brian

osugasman

Update:
1. Swapped horn and fog light relay--horn works fine and fog lights still out--not the relay.
2. Jumped the 30 to 87 pin for 12V override--no fog lights. Also pulled fog lights off and looked for 12V at connector--no voltage recorded.
Appears my problem is downstream from the Relay. Not sure where to go with trouble shooting for this. Not sure it's worth it.

Any thoughts?

--Brian

Garth S

.... only simple, mono dimensional ones ..

Check the 15A fuse in slot #14 ... if the fuse is good, meter the wire for continuity between pin 87/5 of the relay to fuse holder 14 .... and from the fuse holder to the 12V hot side @ the fog light.

Either the fuse is dead, or there is a break in the harness in one of the two runs mentioned.

If none of this pans out, IIRC there is a cross link to relay 30 ... ie, fogs on with low beam, off with high beam or vice versa: wild guess here, as my fogs are switched on permanently to act as DRL's, so cannot verify.

e9stibi

If it is not fuse or relay, it might be a faulty switch. You can remove it and jumper the cables. If you are going this route you need to have the drawings to know what to jumper and test. Just google for "canell UK 993" and you will find what you need.

osugasman

Ok. 15Amp fuse at 14 was fine. While reviewing the excellent 964 wiring diagrams off the Cannell website, it appears the 12V going through fuse #14 pass through Relay 01 as a master and then disburse out to the rear backup lights, daytime running lights and fog lights. Well, my reverse lights have also not worked (ever?) and the bulbs as well as the push button switch off the tranny case were both fine.

I switched out Relay 01 with Relay 23 (horn). Horn still works (implying the relay is fine!?!?) but now I also have functional fog lights and reverse lights!!! Turns out the problem was with Relay 01. I'm not going to look a gift horse in the mouth, but if anyone can explain why the relay won't work in 01 spot and work fine in 23 spot, I'd love to have you chime in.

Thanks, Brian

Garth S

If you flip the relays back to their original positions, and everything still works, then it was a dirty/corroded contact on a pin of the relay .... every time a relay/fuse is pulled, the contact surface is 'refreshed': use of aerosol cleaning sprays also helps.

osugasman

Garth,

Cool. Will try. Your explanation is better than my quiet concern of a cracked circuit board under relay R01.

--Brian

Bradford

Old thread alert......My fogs have never worked. Swapped the fog light switch, still didn't work. Swapped relays, still didn't work. Jumped pin 30 and 87 of relay and now they work. Where is the problem then? Swapping relays didn't help? Thanks

hoggel

LED or HID high beams?

Bradford

Litronics

ayrton

Hope I'm not in OT
I'vethe same problem, back fog lights not working
the relais seems ok, the fuse #14 too, I can measure 12V on it.
the back fog switch lights when off but when pulled the lighted icon is off (usually it should be more lighted)
​​​​​​​the bulbs are ok, what shoul be the problem?

rg0115

I was having the exact same issue and it was starting to drive me crazy. Fortunately, I found this post, turns out I also had a connection issue with Relay 01. Once I removed the relay and cleaned the corroded/dirty contact all went back to normal. Thanks for everyone suggestion on this post. Love it when things work out.