Mopar Muscle Association UK

No, nothing. No dash lights at all I’ve realised. Don’t drive in the dark, so just never noticed.

Absolute disaster of a day and very disheartened, wishing I hadn’t started, as down a rabbit hole now.

Frustrated that I couldn’t find a feed anywhere, I decided for some reason that the connector must be faulty, so cut it off. Still no feed and barely enough wire to connect to new connectors. Struggled for an age with bugger all room and eventually managed to crimp a barrel connector on it, which was all I could manage with the access and I’m now worried about and not happy with. Gave up trying to figure out where to get the voltmeter feed from, and then managed to smash my head into the glove box liner from underneath and trashed it.

So I’ve left with more undone than redone and still clueless on next steps. Need to work out what to do next.

Not comfortable with the state of the wiring under the dash at all, all in a mess and held together with electrical tape, loads of connectors just unplugged and cable ties and home made brackets full of drill holes everywhere. Out of my depth and down a hole.

Assuming top right is the instrument cluster, fuse is intact.

Keep your chin up your doin a fine job!!!
Assuming your sidelights are working? Obviously they are swithched from the same switch but does it rotate for a built in dimmer for the instrument lights or has it got a seperate thumb wheel type dimmer switch? Thats normaly where the instrument lights have their problems in my experience! If its seperate you can by-pass it quiete easily .

That’s a very good question. No separate dimmer, but the lights are on a flick switch, so never noticed a rotating option.

Currently having a thought that I can use the feed for the shifter light to work out the issue with the gauge lights, which then just leaves the issue of why the rest of the dash doesn’t light up.

I’ll nip up tomorrow and check out your suggestion, cheers.

get one of these (most factors have them)

very handy for testing and putting feeds to various units to test they work. (you still have to be fairly cautious as some units don't like 12volts)

there are plenty of videos on youtube like this

Bozwell wrote: Sun Oct 17, 21 8:53 pm get one of these (most factors have them)

very handy for testing and putting feeds to various units to test they work. (you still have to be fairly cautious as some units don't like 12volts)

there are plenty of videos on youtube like this

That’s uncanny, I was watching Roadkill Extra about these earlier.

what year is the challenger? does it have standard dash or rallye dash?

would expect there to be a rotary panel dimmer switch somewhere. either seperate (toggle switch for lamps, seperate roller switch for dimmer B and E bodies i think) or as part of a pull and turn headlmap switch (these might be A body only)

i'd take it out dimmer, start car, then use meter, to find the 12v feed in you will need lights on.
one of the wires will be and should show 12 volts when lights on and 0v when lights off (connect meter between the conector and clean metal on the body/dash)

that proves power to this dimmer switch

(if no power you have a fuse or fuse box issue or the wire is disconnected at the light switch)

if 12 volts found with igntion and lights on,next we need to work out if the dimmer works

mark the feed in and check all other contacts

note any with 12 volts
roll rotary switch back and forth you are looking for a contact that varies voltage with position of switch 0 -12 volts

you may find 2....!

one is for the dome light control and will allow you to dim the dome light or switch it on fully i think only when the doors are shut, i think the dome comes on full power when igntion off lights off and doors open..... can't remeber

one feed is for the dash illumination light bulbs

disconnecting them both and reconnectibng back noteing what goes off will help identify

you want the one for the dash lights

id then use one of these

https://uk.farnell.com/molex/19013-0029 ... price=true

crimp a new wire of long length (red or ornage in your case i think for dash lights)
put this new connector onto the dimmer switch and connect the orginal wire to the piggy back spade

you now have a dimmer controlled feed for any extra gauges lights and its a nice long new bit of wire that you can route over the steering column and along the loom in the bottom of the dash metal work to your gauges by the radio .


If you do not have a dimmer switch for the dash lights..then
you do the same process but this time you are looking for a orange or red off the light switch

it would most likley be the feed to the dash lamps

i.e does it only have 12 volts on it when the lights are on....side, dipped head, or main beam? if so again the piggy back spade and female spade connection can be used.

keep bulbs in gauge lamps to only 12 volt/ 5 watt and you should not have an issue
you need to connect in parrallel so from each guage bulb connect 1 wire to you new feed wire
and either the body of the gauge (metal push fit bulb holders) or if you have 2 wire bulb holders (usually plastic with no metal contact on the push fit surround) the other wire is connected to the car body

if you connect in serial i.e + wire for guage 1 to guage 2 guage 2 to guage 3 and the guage 3's + wire to the new wire the 3 gauge lights will glow at 1/3rd brightness as each will be operating at only 4 Volts. 3 gauge bulbs x 4 volts= 12 volts in total.

you want all 3 to see 12 volts so they each need a wire going to your new feed wire, which brings 12 volts from the dimmer or light switch.

in the picture below the red connector in each is 12 volts and the black one is the car body

left picture the end of each bulb on the red connector side see's 12volts
on the right picture all 3 have 12 volts spread eaqually across them and as the bulbs are all the same its 4 volts across each hence 1/3rd brightness



Dave

It’s a 70 Dave, standard dash, not rallye. Colour wiring diagram currently on way! Unless I’m missing something, I suspect the dimmer is where the immobiliser light is now fitted. Not that that looks like it’s connected to anything either…

I’ll have a read of all that info later, cheers.

well that will explain why the dash doesn't light up

presume dimmer failed and the hole was filled

you are looking for these wires taped up near by

Yellow potentially 2 of them joined at 1 connector
Tan that runs from the fuse box inner end of the fuse holder that is by the gap
a black one from the hedlight switch connects to the connector that is parralel to the dash at one end of the headlamp switch
and its paired with a yellow that goes to a headlamp buzzer or indeed its just a black wire with yellow trace has an asterix so will be fitmnet only in places that mandated a headlamp buzzer

so expect 3 groups of wire for the dimmer

2 yellow to 1 connector top of dimmer
1 Tan wire middle of dimmer
a black and a balck and yellow to the bottom of dimmer

probably in a plastic 3 way conenctor

i'd expect them to be taped up lying in the bottom of the dash or hacked off and taped over near by in the main loom trunk


dimmer switch is expensive
https://www.ebay.co.uk/itm/154004140591 ... SwkflfChxO

but if you don't mind not being able to switch on the interior light

i guess any old12 volt rated 20 ohm potentiometer would work they all have 3 connections and will bolt into a hole in the dash
orginal knob will fit a d shaped shaft






does the dome light work?

Dave

if you want to just not have a dimmer
try below. just link two sections on the connector that hopefully you find lying in the bottom of the dash

dash lights will be full on. when lights are on from now on....

and miss off connection to dimmer switch.
can't think it does anything other than activate dome when wound to 1 end...

instead of taking it to you none exsitant dimmer take it to a standard 2 conector switch with the other switch connector connected to earth i.e its mounting

i belive earthing this cable via a switch will switch on the dome light


hence you keep the ability swich off and on dome light when you need to read a map, on a dark night and have not got your phone

all you will then be lacking is the ability to set dome light to an "atmospheric level" when entertaining
or we can come up with a dimmer from maplins/rs/farnell that will only act on the dome light just need a potentiometer to fill the hole in the dash.


Dave

in the past when being lazy (usually seems to be when fitting a rev counter, lol) i've connected the ignition live i used to power the gauge to also power the illumination.
it could at least make your car useable at night for now until your wiring diagram arrives and you can spend more time on it.
neil.

Crapping ‘eck! That’s a lot of reading to catch up on.

Cheers chaps, will digest and let you know.

From the quick scan, no the dome light has never worked, but if you have a look at the fuse box, there’s no fuse and no connectors either for it.

ok you have a few bits missing

when you get your diagram looks like you will need to ID which bits

dave

After a real Bananarama! of a week, I needed a bit of success, so pleased to say that after another morning of lying upside down on my neck, we have success. A gentle glow from the gauges and voltmeter now working.

Colour wiring diagram should arrive during the week, as will my tach dash mount and cup, so hopefully next weekend will be out for a cruise.

I’ll hopefully get time to digest all the above and get the rest of the panel lights working in the next couple of weeks too, thanks Chaps.

The wiring under the dash really is a horror story, so really need to get it done as I go.

Well done, more positive progress.