Argh! Electrics

[Blitz]

Hi All,
Well i have finally managed to get some time to get back to the build after very little progress at all over the last 18 Months. I have just got to the point where all the wires need to be put somewhere! I know absolutely nothing about wiring what so ever so i have been using the infamous "chocolate blocks" (stop screaming at the PC....i am only using them whilst i figure out where the wires connect to before soldering...saves un-necessary re-wiring) I have mangaed to solder all the front lighting but have noticed that when testing the lights, the power reaches the bulb but it is very dim, the dipped beam and full beam all work fine (Brightly) I have re-cheched the soldered joints and they all look right (Not 'dry') but i am not sure what else may cause this, my thinking is that it is purely resistance on the cable or a really naff / broken joint........or am i missing something?
Any one who can offer some intellegence into my untrained 'virgin' electrical knowledge would be most welcome...
Before i pull my last remaining hairs from my head!
Many Thanks
Neil

[Cerberus]

Have you got a decent earth?


Phil

[Blitz]

Yes, i think so. I re-did it all yesterday thinking along the same lines...the other lights work fine and all use the same eathing point. if it helps one side is significantly dimmer than the other?????
So i am still a little stumped!

[norma]

have you wired the lights in series instead of parallel?

[Blitz]

ah...now its back to the "i know nothing about electrics" bit! what is the difference between the two? I am using the Sierra based loom from premier wiring systems. Each light has its own 'feed' wire. the earth is a shared wire back to the earthing point. If that helps any?

[acrobin]

I used the same loom and it was well documented - check you have wired the block into the back of the bulbs the right way round (assuming you are using H4s) - that was the only room for error I found.

[hearbear]

Using a multi meter check the voltage at the bulb using the earth for the bulb and then put the meter to a good earth eg battery and recheck the voltage. If a big change in readings earth is sus. Also check the bulbs supplied are not 24volt not uncommom.

Cheers George

[rossco61]

Neil's problem with electrics ! As mentioned, could be as simple as a 24V globe in one side. If not, check if problem is the same on Hi beam & Lo beam If yes, then the fault is very likely with the "common" earth. Assuming 65w hi beams, then the current in each "feed wire" is about 5.5 amps, but the common earth wire has about 11 amps going thru it. Hence it must be a heavier wire to carry twice the amps, WITHOUT significant voltage loss !!
If the problem is only on one beam, which-ever, then chase out that particular wiring circuit

Most basic looms use one wire from battery positive, to the headlight switch, then to the dip switch, then thru fuses with one wire each to the Hi beam side of the lamps & another wire to to the Lo beam side. Sometimes this is 4 wires, but often it is only 2 wires that go to the closest lamp, then loop onto the second lamp.
The Earth wire usually is only the same size wire that picks up from the "second lamp", back to the "first lamp" then down to a chassis earth.
Best if it goes right back to the battery negative terminal.

Now, with a good Multimeter, first check battery volts, on the top of the terminals. Should be a full 12 volts. Then turn the lights on. Check again, still 12V ? Now across the battery connectors, then from the positive connector to chassis earth. Still all 12 Volts ? If it is as much as 1/2 Volt lower, FIX IT !! (clean all points!) Continue testing at all terminals, along the way & up to the lamp bases. Should still be better than 11.8 Volts.

Finally, check from the earth side of the lamp back to the battery negative terminal. If you can measure more than about 0.1V then you have a "dirty" connection or too small a wire. Try to measure on the actual lamp terminal pins as you may have a faulty lamp base.
The best way for great lights is to use Relays, but thats another story !!

lotsaluck, ---- Rossco

[Blitz]

Thanks Rosco and Hearbear,
I guess i have some more to get on with this weekend then, and after that i am sure that there will be a million more questions to come!
I will let you know how it works out.
Cheers
Neil

[hearbear]

Thanks Rosco and Hearbear,
I guess i have some more to get on with this weekend then, and after that i am sure that there will be a million more questions to come!
I will let you know how it works out.
Cheers
Neil

Keep the questions coming and if anyone can solve they will no point in struggling with something that may not be a huge problem. I have moments like this at work sometimes and a quick phone call to one of the other engineers can save you a lot of chasing your tail

George

[Blitz]

grrrr......24 volt bulbs! I wish i had known about that BEFORE i re-did all the earths!
Still the good news is that the lights seam to work just fine now.....
Bad news the indicators don't! I can see this is going to be fun!
Thanks for your help everyone
Neil

[whiterabbit]

I have 'untangled' the Sierra 97-99 hazard and indicator circuit from the Haynes book, redrawn it and got mine working ok. I could scan the drawing and mail it to you, or post here if it would be of general interest. I have done the same for the lights and wipers, but not proved them yet.

Steve

[Blitz]

Thanks Steve, That would be great. I make no bones in admitting any help i can get is greatly needed!
I undid all the wiring at the weekend and put it all back exactly as per the "idiots guide" that came with the loom, however the indicators come on with the side lights still! So i am not too sure where it is getting power from. I double checked all the pin conections at the stalks and they all go where it tells me too....and there is no room for error at the light ends (And yes i even triple checked those too!)
So please by all means send me anything that might help!
Many Thanks
A very confused Neil

[whiterabbit]

Here is the indicators / hazards circuit as promised. Note there are two black/white wires to this unit. If you use LED indicators you will need a special electronic flasher relay in place of the standard item, but even then the hazard warning lamp (in the red switch) won't illuminate.

Steve.

[Schrodinger]

Check that all of the lights have a proper and separate earth.
I had a loom where one earth was missing from a brake light IIRC and all of the lights in the cluster came on when I braked, the bl was earthing through the other bulbs. Just worth a check.