rear lights,marker lights and now low beam out

[narfire]

Ok, leaving the shop last night, low beams on, dull but on, go to lock the gate and notice rear driving and marker lights are out. Dash lights out as well. Fiddled with the dimmer switch, no change there, dash lights still out. Drove home wondering where I'll see the road block as there were a number of events in Penticton this weekend including a 800 vehicle car show. Found it about 10ks before home but had the one beer 3 hours previous so good to go. Waiting for a car to follow me and light me up as no rear lights... didn't happen.
On the way home I put my high beams on and they lit up fine but still dull compared to what I think I should have and went back to standard beam with approaching car. Low beam never came back on, total nada, high beams were ok so drove home with them on.
Front turn signals work but will check rears this evening.
Looked at my fuses this am and all good in the holder.
To help me from tearing the car apart, perhaps a suggestion as to where to start? I have the electrical schematics at the shop but suppose I can print off another copy here maybe...

Thanks for any ideas.....

[courtenay]

I'm no electrical expert, Chris, but it sounds like a ground issue to me. Check the ground pods.

[spider2081]

You have a number of different circuits not working. If it all happened at once and you feel it could be a single cause I would first check the battery connections. Then the chassis ground under the drivers floor to the transmission bell housing. From there I would measure the voltage at C31 the ignition switch connector with the ignition switch in the run position and the lights on .

[RRoller123]

Many of us have added a second heavy ground strap. I went from the front of the block, passenger side, up to a bolt on the fender inside wall. Purchased preassembled at AutoZone, etc; with ring connections both ends.

[narfire]

"I went from the front of the block, passenger side, up to a bolt on the fender inside wall."

I have the same.
I have a feeling it is a ground plug. I'll seem to remember one under the dash then I'll check the fender ground cluster. My horn is not working either....
34 deg C at the moment so I'll wait a bit before mucking about on the car.

Thanks gents.

[narfire]

Update: Likely the circuit board..... got the rear driving light to work on drivers side....bad connection at the bulb and the rear left marker light.
brake lights work both sides. put a multi meter on the terminals on the passenger side circuit board. Nada except brake lights circuit.
Cleaned fender ground pod but still no head lights, just hi beam and no horn.... Flashbacks 40 years ago with my first car...70 124 spider. Some things will never change especially Fiat electrics.

[spider2081]

I am pretty sure your driving lights, some call them parking lights, are on fuses 7 & 8. 8 is left side front and rear and 7 is for the right side. I would measure the voltage across the fuses, one meter lead on the top of the fuse and one on the bottom of the fuse. The voltage should be very close to zero. Anything greater than 0.5 volts means there is a dirty connection on the fuse contacts. Being as you are finding separate causes for some of the issues they probably did not all happen at one time meaning there is not a single common fault.
If you headlight circuit is stock you have 4 fuses for the headlights. 3&4 are high beam and 5 & 6 are lo beam. If it has relay mod installed then both lo beams could be on one fuse and operating through one relay.

Lights and light sockets need periodic maintenance. The bulbs should be removed and cleaned and their sockets cleaned every couple years. Bulbs should be lubricated with a grease or oil when installed to reduce corrosion and rust development.

[RRoller123]

Check that ground wire in the trunk, on the driver's side, maybe 8 inches or so to the left of the center latch mechanism, driver's side. It grounds a bunch of stuff.

[narfire]

Thanks for the suggestions. Got the rear lights to work again. cleaned the rear boards and connections.
Got sidetracked though, happens with these cars....the rear muffler bracket that is connected to the car, started to hang down as the metal has started to tear. Took the spare tire out. jacked the offending part up to flush, spot welded it together then took a piece of thin flat-bar and bolted that to the floor of the trunk then bolted the strap through the shite metal and flat-bar and everything is back...sort of. Muffler is sitting a bit high and touches the strap at times giving a resonance through the car....
Man, would I love Mark's snake-head headers and exhaust/ tailpipe...the 28% exchange at the moment prohibits this...bummer.

Going to take my dermal and thin wire brush to the fuse holders to see if I can get the horn and low beams to work.