Indicators and Hazard Lights New Problem

[bcrain]

My 88 Caterham has an odd indicator problem I have not seen before in tech talk. When switching on either left or right, the opposite side comes on at about 1/4 - 1/3 power also. I suspect the the hazard switch because the hazards were causing the flasher to buzz instead of switching until I actuated them several times. Now they work, but can't get the indicators to behave. Suggestions?

I'm also confused about the single lamp used to show that the indicators are on. It is not working. The diagram show both the GR and GW wires going to it, but no path to ground. Is that done by the metal instrument panel? Is there some path through the "unused" GR or GW wire to ground?

One more thing, there is a white block on the back of the hazard switch. I assume this is a multi-pin connector, but I can't get it off.

[Jonathan Kay]

Do you have a multimeter and would you like a wiring diagram?

Jonathan

[Jonathan Kay]

"My 88 Caterham has an odd indicator problem I have not seen before in tech talk. When switching on either left or right, the opposite side comes on at about 1/4 - 1/3 power also. I suspect the the hazard switch because the hazards were causing the flasher to buzz instead of switching until I actuated them several times. Now they work, but can't get the indicators to behave. Suggestions?"

That sounds like the common problem inside the rocker type hazard warning light switch, and I'd start with exploring that.

There's a *full explanation in the archives, but you can sometimes localise the fault by working the switch a few times and seeing if that has any effect. 

If it does then you can open the switch and clean the contacts. Or buy a new switch from Redline.

...

The next most common problem is probably the indicator unit ("relay") and its connections. Inspect the pins and check the seating. Then try another unit.

...

Jonathan

* Why it causes the strange effects, and an improved circuit design that removes the problem.

[Jonathan Kay]

"I'm also confused about the single lamp used to show that the indicators are on. It is not working. The diagram show both the GR and GW wires going to it, but no path to ground. Is that done by the metal instrument panel? Is there some path through the "unused" GR or GW wire to ground?"

It's one of the two funny circuits. The circuit is completed through the indicator lamps on the other side of the car! Circuit diagram.

(This is why you can't do a straight replacement of the incandescent dash bulb with an LED... )

Jonathan

[SM25T]

Also check the flasher units are pushed home in their bases. Sure that white connector should just pull off the hazard switch. Maybe corrosion on pins/sockets ?

[bcrain]

Thanks for the responses. Yes, I have already checked flasher/relay seating and multi-actuated the hazard switch. Looking at my 1988 wiring diagram (thanks Jonathan from 2018), I thought there was something funny about the indicator on light. It doesn't surprise me that that that is the way it is. Auto electrical designers are notorious for taking short cuts. It may be that when I converted to LED front indicators that the indicator on light quit working and I did not notice right away (thanks Jonathan for the motorcycle LED conversion info, I'll implement that). One day, I want to convert the indicator on light to dual LEDs that pick up ground directly; that way I can see which is on like on most cars and dial in the brightness I need since the signal switch is manual.

It appears that leakage is my only problem other than a typically balky hazard switch. Tool wise, I have everything, up to digital storage oscilloscopes.  I can build most anything. What I don't have is a young pretzel body for removing and replacing instrument panel items without taking off the scuttle. I would like to have some advice on removing the indicator light for redesign without the aforementioned pretzelization.

Thanks for the info, Bob

PS. Any reason for buying a hazard switch from Redline vs. Caterham?

And why does the spell checker in Techtalk highlight Caterham as a misspelled word?

[SM25T]

R vs CC .... it is the same part, but slightly cheaper from R.

[Toby S]

Must admit on my 1992 supersport, I've always managed to disconnect the white block behind the hazard and also the headlight and other switches and get the switches out (as well as the big white block you'll also have 2 other wires at the top and bottom of the switch which powers/earths the nightime illumination which can be a bit fiddley when refitting and you can get a short and blow a fuse when refitting if you're not careful)

 

Once out I've dismantled the switch (they are just clip together) to clean all the inner copper workings - they are both fairly simply switches and typcially a clean up of all the copper bits (sliders and contacts) does the trick and gets them working as good as new

[bcrain]

I got everything fixed. Indeed, the switchover to LED front signals caused the problems. I got a neon panel light with a clear lens that fit the hole and removed the guts. Then I put a red and a yellow LED inside and added the third required ground wire. Now the panel indicator flashes yellow for left, red for right and yellow/red for hazard.

Word to the wise, I had to remove the speedo to get access and when I put it all back together the panel lights did not work - fuse blown. It seems that even though the panel lights inserted in the speedo are in a plastic sleeved socket if you get the black (ground) wire in the center conductor it shorts out and blows the fuse. After 2 fuses, I got it sorted. Something must happen inside the housing.

Thanks to all for the advice.

[Jonathan Kay]

Well done. Thanks for the update.

...

IF you have a single indicator warning light in the dash

AND want to change to LED indicator lamps

OR want to change to an LED indicator warning light in the dash

THEN it's possible to do this with a couple of diodes and and a new earth.

Jonathan

[Colin Park]

Duncan Rikards of Classic Car LEDS 08002465678 sells a ready made diode kit to get over this problem. 
Its something to do with both indicators being controlled by the one switch on the dash 

[Jonathan Kay]

The explanation is linked in post #4 above.

Jonathan