Amazon: Wiring

[222s]

Following on from this thread, I've been wiring in a switch to cut the reverse lights as the gearbox switch is stuck on.

I chose an illuminated one as then I wouldn't forget to turn them off. The switch has three terminals, which I wired as follows:

'Ground' - just as an earth (for the toggle switch light)

'Acc' - to the gearbox switch

'Power' - from the relay

The lights switch on & off, but with the ground wired in, the light on the switch works but the 16 / 17A fuse keeps blowing. I've run out of the correct ones (currently on an 8A one) so have unplugged that for the time being.

Have I wired this switch wired correctly? with just the 8A, the relay etc all works fine when the new switch is operated but haven't tried with the illuminated part as I don't have any more fuses!

Also, the headlight flasher & interior light have both stopped working completely. The interior light was fine earlier today, and although the headlight flasher has been tempermental, until now I've always heard the relay click.

Are these connected? Shared fuse perhaps? The card info piece inside the fusebox is missing so I don't know which fuse runs what.

Oh, and today I also replaced the map light (new pull switch as the old one was jammed solid, but it won't work. The bulb is fine as I've tested it elsewhere.

Any help sorting these out would be much appreciated!

Cheers,

Paul

[Ron Kwas]

Paul;

If you're blowing 16A fuses**, of course somethings wrong(!), but the info you give is a bit confusing...you need to investigate one thing at a time. First: Which fuse is blowing? If No 2., then refer to wiring diagram here: http://sw-em.com/122S%20Wiring%20Diagram.jpg ...and this will also help you to figure out what circuits are supplied by which fuses.

Interior and Revering lights are not normally on the same fuse, but if they were, (and the little ball bearing in the switch of interior light fell out due to lack of lube), that has been known to cause a short an will blow Fuse 4.

Good hunting!

** My sure fire way and simplest way to locate a short without blowing more fuses:

1. After fuse blows, locate fuse power input side terminal (of said fuse) with a Multimeter set on voltage (do this without changing any other conditions - like position of IGN switch - Always limit time IGN switch is ON and engine is not running to prevent overheating IGN coil. ). [Input side will have 12V power, (shorted) load side will have 0V.]
2. Disco battery
3. Connect an Ohmmeter (with continuity beeper/buzzer function) to load terminal and chassis. [Will beep/buzz to indicate short/connection to chassis].
4. Visually check carefully, then probe around and disco wires at 1)...those circuits and loads supplied by that fuse...2)...any place you suspect a problem (like where you saw smoke coming from), or...3)...anyplace you made changes or mucked around with the electrical system last....until beeper/buzzer stops indicating a short is present.
5. Once short is located, fix should become clear.
6. Affect repairs, recheck with continuity checker, when repair is confirmed, recon bat, turn IGN OFF (if it was ON during troublesooting), install new fuse.
7. Recheck functions work under power conditions.

Good Hunting

[222s]

Many thanks Ron - I'll have a close look at everything later on after work.

Yes, it's No. 2 fuse blowing. Only happens when the third terminal on the illuminated switch is run to earth. Otherwise the new switch seems to work fine (I can check when I operate it as the back seat is currently folded down & one of my boot trims is damaged, and so it's possible to see the reverse light illuminating inside the rear 1/4.

[biggles24]

Hello,
You have probably sorted this by now but I only just saw your post.Idont understand "stuck on" concerning gear box switch.This is probably the crudest bit of kit on the car.Why dont you just take it off and fix it or bin it?It is externally mounted, just in front of the prop shaft flange,on a vertical surface of the gearbox.You will see a wire on a spade connector on the top of this small metal box,which is secured to the gearbox by two screws(Phillips screws ).Take them out (a bit awkward to get at because of the prop flange)and the housing is off.
The only thing in this housing is a small spring connected to thespade terminal on top. If this is broken or missing or jammed in some way you have solved the problem.
This crude switch works when reverse is engaged and the rail in the gearbox moves back and the end projects into the box you have just removed and makes contact with the small vertical spring, thus completing the circuit for the reversing light. HTH. Regards biggles24

[222s]

Thanks for the explanation on how it works. Unfortunately though, I can't get sufficient access to the switch since there's also an overdrive in the way...

[Derek UK]

I read your earlier thread. If the problem is the GB switch, all that does is ground out a connection on the relay in order to complete the circuit for the reverse lights. For a manual reverse light switch you only need a simple 2 pole switch in a wire from the same relay contact to ground. To test you only need to short out this connection under the bonnet to prove the circuit. If that works OK a single wire from the relay to your dash switch and then to ground should do the trick.
I'm always wary when posting what seems like a simple solution to a fault that's causing problems.

[222s]

The rest of the reverse light circuit is fine. I currently have a dashboard switch wired in, but getting it to illuminate is the problem, as once the third terminal is wired in, the fuse blows soon afterwards. After destroying several fuses, I got bored and gave up trying to get the illumination for the dash switch working. Going to wire in a separate light (in series with the switch) so that there can be no error in the wiring scheme. Once the gearbox light is sorted out, I'll use the switch and light for something like foglights or a heated rear screen.

[Ron Kwas]

222;

"...(in series with the switch) so that there can be no error in the wiring scheme" ...would be incorrect immediately!

To be a proper indicator, a wire needs to run from the power side of the load (and this node is ONLY available at the output side of relay, or load itself), and routed back to power the indicator (be it within switch or seperate). Anything else is just an indicator of the state of the switch, and so not a true indication of the power state of the load.

Since you already have been blowing fuses, and now make a statement inconsistent with what would work, you might want to engage the local assistance of someone electrically qualified.

Cheers

[Derek UK]

Following on from my "wary" suggestions.........
"Acc" stands for accesory. i.e. what the switch is suppling power to. A spotlight, electric fan etc. If you connect it to the GB switch you just switch power to earth. This would be a switched short circuit, not very useful.

Fuse box - top dumpy fuse -wipers, heater fan. washers, Blinkers, charge, oil pressure, fuel, overdrive.
Fuse 2 - Horn, stoplight.
Fuse 3 - Panel, reverse, parking.
Fuse 4 - Headlight flash, interior light

[michael lyttle]

What is the likely reason my reverse lights stay lighted with the ignition off if the transmission is in reverse? Also is it normal wiring for the panel lights to illume with the ignition on or in acc without the light switch being on? How can I get the panel lights to be brighter? Can you send a pic or diagram of the wiring for the dome light (black,blue,ground)? All this wiring is inside the fixture right? Thanks for your help.
1964 Amazon 122S And unrelated, I could use a clear picture of a properly installed dash pad Thanks again