No dash lights,what are these plugs?

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Goblinking
Posts: 71
Joined: Wed Aug 12, 20 2:19 am

No dash lights,what are these plugs?

Post by Goblinking »

74 challenger.
I had no dash lights except the footbrake working,so i took the dash apart and found the oil light broken and
The other bulb missing.
Now i have no lights working,after new bulbs have been fitted.
The car starts and the indicators work and flash on the dash,headlights work,but nothing else lights up.
I tested the dimmer switch and it seems fine,wipers dont work though.
Does anyone know what the 2 white plugs behind the light switches are for?they were not plugged into anything and whats the deal with the random wire jammed into the fuse box?
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Dave999
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Location: Twickenham,London, England

Re: No dash lights,what are these plugs?

Post by Dave999 »

the only place on my car that has a connector like that is the connector for the indicator switch, my Aussie car would trail US improvements by a couple of years....but still they look a bit too modern.. wonder if it had an aftermarket immobiliser

to be honest without knowing where the wires go, its going to be hard to say, i take it they do not connect to each other.

i mightbe wrong.. could be standard...but look too new

basic dash illumination is usually 1 feed wire from the light switch rotary dimmer up to the dome light, back down to the 3 or 4 basic illumination lights in the dash. ro dome light also has added complication with the door switches

the rest are part of their respective circuits indicator oil brake etc power to switch, but bulb not lit until a switch in the circuit somewhere completes the circuit to the light in the dash which has 1 pin of the bulb earthed to the dash pod is the usual way.
unless the bulb is in a 2 wire holder.

wipers won't work unless the switch is properly earthed to the dash frame. take photos before disconnecting wiper loom at either end
dash lights don't work unless the metal case of the dash pod is earthed to the dash
dipped and main may not work unless the dash pod is earthed to the dash

additions to fuse box. someone has added a live feed for something extra off the end of that fuse.. Normally you would apply this to a spare spade on the back of the box or indeed a spare fuse position, i guess haste or inaccessibility to the connection side meant a bodge to the fuse side...
fusebox is usually split into switched and not switched sections the not switched section is live all the time....you clock would be on one of these fuses along with dome light and at least side light/parking lights potentially radio if it had a clock . the switched side only gets power when ignition switch in in ON or RUN or START position. working out which section might dictate what it is for or what it might have previously been used for.

i think a wiring diagram is in order.... dig out a manual for the right year from www.mymopar.com

lack of dash functionality

bad bulbs
holders too loose and fallen out
resistance/corrosion in holder or at the push fit contacts for bulb or holder
knackered 5 volt 12 volt regulator but if your fuel gauge works discount this issue.

can of deox or deoxit electrical cleaner or any of the cheaper ones CPC etc. (or elbow grease a file some wet n dry and Vaseline ) every fuse connector and holder, and your ignition switch and see if it improves

i'm guessing i'm sure you can tell :)

Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
Goblinking
Posts: 71
Joined: Wed Aug 12, 20 2:19 am

Re: No dash lights,what are these plugs?

Post by Goblinking »

Dave,Thanks for that comprehensive reply,it was an earthing problem in the end.All sorted now but by God,the dash lights are dim.
I thought the same as you about the plugs,they look too modern.
The wipers move now,but very slowly.
Thanks for that link,what a class site,its going to be very helpful.
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Dave999
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Location: Twickenham,London, England

Re: No dash lights,what are these plugs?

Post by Dave999 »

no probs

the cars have, in modern terms, simple electronics, trouble is they are just complicated enough to very confusing..

often easier to switch the thing on and work back from the far end until you find Power and replace fix the wire there..

but often corroded earth missing earth or loose. is the problem

any original taped up loom, provided nothing has melted, will still be in good nick. most of your issues will be the last 6 inches on any wire or the impact of Mr Bodge it with his blue snap lock connectors

Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
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ScottyDave
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Re: No dash lights,what are these plugs?

Post by ScottyDave »

Dave999 wrote: Thu Dec 10, 20 9:31 am blue snap lock connectors

Dave
a lot on mine was just insulation stripped back and the new wire just twisted around then covered in tape...
73 Charger 318
MMA-130
Goblinking
Posts: 71
Joined: Wed Aug 12, 20 2:19 am

Re: No dash lights,what are these plugs?

Post by Goblinking »

Just to follow up on this in case anyone has the same question.
The white plugs are for something called the seatbelt interlock system module,a well loathed idea fitted to 1974 cars.
Image
and the wire shoved in to the front of the fuse provides power to the light bulb on the gear selector.
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MattH
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Location: Bedfordshire

Re: No dash lights,what are these plugs?

Post by MattH »

I put much brighter bulbs in my dash lights. Almost essential as the dash is flood lit from the front with blue filters, not behind like most cars. The dimmer improved with use, it was just on or off.
Matt Hollingsworth - Vehicle Registrar
Panther Pink 73 Aussie Charger 265 Hemi 4 spd
Challenger Sam Posey Tribute car
Goblinking
Posts: 71
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Re: No dash lights,what are these plugs?

Post by Goblinking »

Yes Matt,a good idea,i might try led bulbs.
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Dave999
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Re: No dash lights,what are these plugs?

Post by Dave999 »

if your dash uses blue/green "Gell" domes over the lights to give it its distinctive look when illuminated

i found it nigh on impossible to get mopar ones and those i found second hand were expensive

But chevy and ford guys seem to give these things away, i(n comparison) and they fit... seems to have been used by GM and ford up to the mid 80s

Dave
The Greater Knapweed near the Mugwort by the Buckthorn tree is dying
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