ausmini
https://www.ausmini.com/forums/

Electrical gremlins
https://www.ausmini.com/forums/viewtopic.php?f=2&t=45129		 Page 1 of 1
Author:  richarde [ Sun Aug 24, 2008 3:31 pm ]
Post subject:  Electrical gremlins
Hi all.

I have an electrical problem on my car and thought I would post on here before I get too far into my investigations in case anyone has had similar issues or can point me in the right direction.

It all started about a year and a half ago, when I found that while driving the left indicator would flash occasionally for no reason (I only noticed this at night). I checked the light assemblies and couldn't find anything wrong with them. Then I left if for a while. Some time after that the horn and interior light stopped working. Then, after another month or so they worked again, and everything seemed fine (I didn't notice the left indicator doing the random flashing after this, but that is pretty hard to notice while you are driving and you can only see it at night).

The most recent development is that when I am driving the left indicator will come on when I reach a certain speed (or maybe a certain gear?) and stay on until I brake or indicate. If I brake or indicate the indicator stays on for a bit before going off or starting flashing (i.e. there is a delay).

So currently everything is working apart from that indicator coming on at the wrong times and whatever. As far as I can tell everything else is fine - both brake lights work, the other indicator works, headlights work etc. I am not sure whether all the problems I have had are related or whether I have a number of problems, but I would assume that the two problems with the left indicator are related to each other.

The ticker unit under the dash makes ticks if I indicate either way (as it should). The indicator speed is dependent on engine RPM (which I assume is normal).

The only attempt I have made at fixing it so far is to add an earth strap to the (LHS) tail light assembly to make sure it was earthed properly and it didn't help.

The car is a '76 clubby but I think the wiring matches a '75.

Anyone have any ideas? I was thinking of replacing the flasher unit next.

Richard
Author:  Mike_Byron [ Sun Aug 24, 2008 5:23 pm ]
Post subject: 
There is two problems to consider.

One is that somewhere in the dash there is a bad earth.

The second problem is that the indicator mechanism is on its way out. What happens is that the high beam beam/low beam carries too much current and over time with the arcing the contacts burn and short.

You may be up for a new (or good s/h unit). Its under the plastic surround which goes over the steering column.

Now the same thing will happen again eventually so you need to see an electrician to fit some relays for the lights so that the indicator mechanism, where the high/low beam switch is, does not carry such a big current. So that it is simply a switch.

I almost bet my bottom dollar that that is where your indicator problem is.

Mike
Author:  richarde [ Wed Aug 27, 2008 11:03 am ]
Post subject: 
I have heard about the problem with not having relays on the lights before and that it affects the switch in the dash, but I didn't realise it also affected the indicator stalk. I already have the cover off the steering column from when I was looking at the indicators before and didn't put it back on.

The problem of a bad earth in the dash doesn't sound like a fun one to try to solve and I have a spare indicator assembly (which I assume is still in decent condition) in the parts car, so I will pull that out over the weekend and swap them over and see if that fixes it. If it does then I will look at fitting some relays for the lights.
Author:  peterw [ Wed Aug 27, 2008 12:52 pm ]
Post subject: 
I agree about the bad earth. When you get a bad earth in a circuit it will look for an alternative path to earth and if the path of least resistance is through a globe then the globe will light up.

Probably worth going through all areas where the wiring loom goes to earth and cleaning the contacts.

Pete
Author:  pristic [ Wed Aug 27, 2008 12:58 pm ]
Post subject: 
My money is on the indicator stalk. If you get it to the 'revs' or speed where it 'comes on' and then touch it gently does that affect anything, they get sloppy sometimes and the blinkers behave oddly, or they get sloppy and allow current from lights etc into the rest (eg, blinkers)

Pete
Author:  Blackdog [ Wed Aug 27, 2008 1:08 pm ]
Post subject: 
my instrument cluster just recently went back together after a long time disconnected.
it was doing some wierd and kinda similar things but just because the connectors contact with the sheet at the back wasnt too good.
Doubt thats your problem though. I'd agree with the other responses especially cleaning up contacts.
NT
Author:  richarde [ Thu Aug 28, 2008 9:01 pm ]
Post subject: 
Well, I tried out Pete's suggestion for testing except I didn't get to test it while wobbling the indicator stalk because I have found what I think is the problem before I got to that.

I found that the indicator comes on when I put it in 4th gear. Also, the left indicator is the only one that comes on when I put it in reverse. Additionally, the rubber support on the gearshift is broken (has been broken for ages but I never got around to it :P).

So my suspicion now is that the switch is triggering for the reverse lights when I put it in 4th gear (which, of course is right next to reverse). This may be due to a change in alignment because of the broken support, or some other electrical problem (broken or misaligned switch, earthing problem etc).

I also need to investigate why the right rear indicator isn't coming on when I put it in reverse (possibly due to the same problem).

It also appears as though the previous issues were unrelated (I can't see how they are related anyway. The previous indicator issue caused both indicators to flash, not just the back one).

I will replace the support on the gearshift over the weekend and see if that helps, then start investigating the switch and wiring if necessary.
Author:  Morris 1100 [ Thu Aug 28, 2008 9:08 pm ]
Post subject: 
If it is a rod change box the wires for the reversing lights are clipped to the subframe and they will snag on rocks and things. It would be quite easy for them to have splits in the insulation somewhere.

The reversing light globes are a dual fillament and you can have a blinker that works and no reversing light in the same globe. (try turning the globe around half a turn?)
Author:  richarde [ Thu Aug 28, 2008 9:14 pm ]
Post subject: 
Yep, it is a rod change box, and the wires are hanging a little low because a couple of the clips are broken. I haven't taken it over any rough road for a while though.

I am hoping it is just a misalignment due to the mount being broken because it is twisted quite a lot (which is the reason I haven't replaced the mount yet - I may have to fiddle with it a bit to make sure it isn't under tension or it will just break again).

I will check out the globes over the weekend too, but I haven't replaced them in ages, so I don't think they would be installed half a turn out (I'm not sure if you can install them half a turn out anyway). The filament may be blown though.
Author:  richarde [ Tue Sep 09, 2008 1:26 pm ]
Post subject: 
Well, I replaced the mount on the gearbox over the weekend and the reverse lights are working properly again (apart from the blown globe) :D

Thanks for your help guys.
Page 1 of 1 All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/