can someone check my indicator circuit theory please

[fredster]

Right - got to tackle my indicators as I'm fairly sure my switch is buggered but with them being best part of £100 I want to be sure it is the switch before buying. Electrics are not my strongpoint, but is this roughly how indicator circuit works:

1. 12v pos comes from battery, thru headlight switch then fuseboard then hazard switch to indicator relay.

2. When indicator is turned on by lever, the 12v signal (pulsing on/off now after passing thru ind. relay) from relay is connected to relevant indicator terminal on switch and on/off signal then makes its merry way along wire to indicator thru bulb and to earth.

Is that roughly how it works?

At present my hazards all work fine, which suggests to me the hazard switch and the relay are functional. When I indicate left or right nothing happens and the gen light comes on. Genny output is not award winning (bought new one today) so my theory is that signal from relay is being fed to earth by dodgy switch, causing current drain and genny light on. I would have thought that a fuse would blow, but there you are.

cheers in advance
fred

 

[58herbie]

Fred,

Have you got an indicator warning light working on the dash, as the hazzards do not need this as there is one built into the switch. without the warning light the indicators will not work.

the wires to make this work are a blue with red trace from relay and black which is ignition fed live which comes from the fuse box (easy to spot as at the box it is in the same crimp as a green wire).it then goes to fuel stabaliseur and then feeds the rest of gauge cluster.

jon

 

[fredster]

Thanks Jon, will give it a go and report back.

 

[fredster]

Right, feel I might be getting somewhere. Tried your tip Jon, With hazards on the blue/red wire from relay terminal KBL is only putting out a tiny amount of voltage - between .3V and .5V and certainly not enough to light up a test lamp.

So 2 questions:

1. Do the indicator warning lights on dash normally flash when hazard lights are on?
2. Do these small instrument cluster bulbs only need a tiny amount of voltage to light, being so small?


cheers
fred

 

[58herbie]

Fred,

The blue/red wire is more of an earth wire the live wire for the dash lights is black.

hope this helps

Jon

 

[58herbie]

Fred,

Just another thought. i know from your other post u have recently converted from us spec to uk, have you changed light units etc.. what are you using for rear indicators..are the bulbs the correct wattage..

had the very same problem on Nelly's bus, Travelled 300+ miles to help him as i said i would checked my loom that i had made no nothing wrong there... Problem.....wrong wattage bulbs (Nelly had bought some LED bulbs that where sold as indicator ones). worked with hazzards due to the way the switch supplies power to all 4 at once so the relay balanes out. But the coloum switch was the same as yours, Nelly even bought a new switch before i got there and tried but still the same..

If you have wiried it so your indicators are now in your reverse lights these bulbs are only 5 watt instead of 21 watt..

hope this makes sence and helps..

post some pics of what your using and i can help u more

Jon

 

[fredster]

Cheers Jon for yet more vital info - I have indeed used the reverse bulbs (painted orange) as indicators. Will the wattage difference cause problems?

Actually, thanks to your last post I've finally had a breakthrough. I measured the voltage of the black wire you mentioned that brings power to indicator warning lights on dash and it measured 10.5 volts, whereas the voltage at battery measures 12.6 volts with engine off. I finally traced the problem to the ignition switch. Big red feed from battery going in measures 12.6, wires coming out measure 10.5v, fluctuating a bit depending on fine movement of key position.

Moby on VZi forum suggested I check my fuse ratings and sure enough, fuse for the black wire was 15A instead of eight, as I had incorrectly got fuse ratings from a later bay (75) manual for fuse ratings. I put in a 8A and they work now, although the warning lights are still hit and miss, which hopefully will be remedied by overhauling ignition switch. Am I right in saying all fuses should be 8A ?

So to summarise my problems were/are thus:

1. Ignition switch is robbing voltage.
2. Relevant fuse was too big - not sure how this affects it to be honest, but it did make a difference when corrected.
3. Alternator is pretty darn tired pushes out 13.6V at best so battery never fully charged. New one ordered.
4. Using incorrect wattage indicator bulbs at rear. This will definately cause problems will it?

Thanks once again for your input. Getting there now. All indicators flash as they should, but need to sort warning lights on dash.

fred

 

[58herbie]

fred,

All fuses should be 8 amp except the ones that have the main + (red wires) through them they should be 16 amp.. what sort of fuse box do you have a black 10 fuse or white 12 fuse this will determine the position of the fuse, as for the size making the difference can't really see it all the fuse does is act as a weak spot in the system. so should there be a problem that blows. but if the wrong size is installed then thats when problems arrise. As the wire or components it should pretect become the weak spot.

Now onto the bulbs..yes you need to change them, having the wrong wattage will affect them. the relay is designed to work at 4x21 watt + 5 watt for the warning.. if you put different bulbs in it will either not work at all or flash fast as it thinks one has blown when you use that side..

hope that helps

Jon