saudivette

Hi, I had my dash in bits this morning and all the gauges out. The tacho wasn't working before I pulled it out and it's still doing the same thing.

The needle sits well below the zero point with the ignition off. When the ignition is turned on, the needle drops sharply a bit further. It's only if I rev the engine up quite a bit that the needle will flicker up a bit.

When I had it out, I noticed some dicolouration on the circuit board, does it sound like something on it has burned out?

2nd question.... When I bought my car, the headlights had been left up as the prvious owner hadn't been able to work out what was wrong with them. I discovered that the headlamp relays each had the centre tube broken off. I managed to repair the both of them and fit everything back today. I pulled out the original hoses as they were all buggered, and put in new stuff. I didn't think of hose lengths at the time....

The headlights work, but when I turn them on, nothing happens for maybe 5 to 10 seconds and then the drivers light slowly raises. About 15 seconds after that, the passenger light slowly raises. They close at the same time though....

Anyway, is it the hose length differences causing the delay between the light the drivers and passengers light popping up? I assume I have a vacuum leak somewhere that would be causing them to wait so long before they come up, but what is the most likely offender?

Z-man

Maybe it happened when someone cut all those wires out and laid them on the sidewalk!!!

I don't think the difference in length causes the delay between the two. I think it's a matter of that there is a certain volume in the actuating pistons that takes a time to evacuate. The headlight with the slightly weaker spring and therefore less resistance will pop up first, then the other. I've never seen a C3 where both lights go up exactly at the same time.

In addition to all the hoses, I'd check the line from the engine to the vacuum cannister and the cannister itself. Then there are the actuators. If the lights are going up and down, the main diaphragm in each one is probably OK, but look at the seals on the shafts. After time, these can develop small cracks which are leaks. I replaced some of them on mine and the lights work much better.

saudivette

Nah, I'm a big scaredy cat when it comes to electricity - I only cut one end of the wires (the other ends were hanging around behind the block, not attached to anything) and the tach was doing the same thing before and after

I replaced all the hoses for the lights, but after reading around this forum and the net, I've realised that I don't have the filter or check valve that go on the back of the intake manifold. Dunno whether the filter is such a drama, but I assume that the check valve was originally installed for a reason...

You'll pardon my innocence, but I actually thought the lights were supposed to come up at the same time..... :blush: :bb makes sense with your weaker/stronger spring theory though

A C

Sounds to me like you might have a bit of a vacuum leak somewhere. Check the vacuum tank in the fender, they are notorious for developing pinholes in the bottom. Either that, or a large cam. That would explain the slow opening. I do remember with the extremely large Crower cam that used to be in my car, I would actually have to get out and give the lights a little pull or they wouldn't come up.

Ak. Mal

Sounds like your tach circuit board might be bad. Mine read twice the actual rpm before I replaced it. It's a simple part to replace.

saudivette

I had a look at the coffee can (insitu) and from what I can see, it looks ok. I think I'll pull it though and bury it in aircraft sealant!! I also discovered that the check valve up near the carb was missing... Ecklers have been contacted!

saudivette

When I pulled the circuit board off, it had some browning on it, but I wasn't sure if it was burned out or not, as all the components on the board looked ok. A new circuit board however, was ordered at the same time as I ordered a check valve for my headlights

Ecklers must love me by now...

Mike Ward

They are supposed to go up and down simutaneously, it's just that very few cars have a vacuum system that's 100% leak free. You have a leak somewhere, most likely a shft seal on the 'slow' side.