Author Topic: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions  (Read 4613 times)

Offline Moneypit440

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I picked up a 383 4 speed and there are several electrical issues.  I printed out the electrical diagram and have a very limited understanding of electrical issues, but I think I can at least trace wires based on the diagram, to the extent they are reasonably stock set ups after 44 years!  As a rookie, I will appreciate any insight you guys have, unless it results in me being electrocuted.

Here's what I have:

First, I also have a 1970 Challenger R/T, and each car has the 3-switch panel to the left of the rally gauges.  However, the cuda also has 3 aftermarket indicator lights set in the dashboard.  Two of them were not connected to anything and I removed them.  I haven't checked the third one yet.   I have no idea what purpose they served.

The dome light does not work.  I touched the bulb outlet contacts with a circuit tester and the driver's door open, and sparks started flying where the tester touched the contact.  I assume power is getting to the outlet but maybe there is a short?  Any idea what I should do to try to repair it?

The fog lights are in the passenger floorboard along with about 5 feet each of wiring.  They don't help much there.  With the wiring diagram, should I be able to reinstall and connect them?  Also, what makes them turn on/off?  The headlight switch?

None of the fender lights/blinkers work.  I frankly haven't even checked them for bulbs.  I also have not tested any fuses.  Should it be reasonably easy to get them working with the wiring diagram, even if I have to replace the outlets and/or wiring?

Headlights, tail lights, brake lights, emergency flashers, rear and front blinkers and reverse lights all work.  However, when I use the right turn signal, the left tail light stops working while the right taillights are blinking.  Any idea what that might be?

On an unrelated matter, I removed a valve cover to confirm head casting type and date.  I noticed that the valve cover bolts were several different types, some with as many as 4 washers.  Without confirming, I assumed they were a mis-matched set of various lengths with the washers used as spacers.  So I ordered a set of Mopar big block valve cover bolts, and they also need the extra washers to fit tightly.  The valve cover appears to be OEM stock.  Is it possible that the thickness of the valve cover gasket is keeping the bolts from seating all the way, thus the need for extra washers?  Plus I broke the head off of one of the mixed set of bolts tightening it.  That's another problem I have to deal with.  It protrudes a bit from the head but pliers won't turn it.  I will try vise grips next I suppose.

If anybody wants to swing by and restore everything to factory stock that will be fine.  I will even buy you a donut or two.   Otherwise, any advice will be much appreciated. 
1970 Challenger R/T 440 Magnum/727 Torqueflite
1970 Cuda 383 Super Commando/A833 4-speed
2010 Challenger R/T Automatic w/Magnacharger/CAI/Catback Exhaust Upgrade




Offline Chryco Psycho

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #1 on: September 12, 2013 - 11:51:37 PM »
The dome light has power all the time & a 2 contact bulb where the ground is connected either at the doors or headlamp switch so you should have power with a test light but it should not short when tested .
 The fog lights have a separate switch 
 The fender lights have a small bulb easily tested with a meter & the housing needs to ground under the fender .
 The taillights have a grounding issue also the housing has to ground to the body .
 There are 3 types of valve cover gaskets cork rubber & rubber coated fiber & they do vary in thickness , tough luck on the broken one they can be tough to remove , usually a pin punch & try to tap it to rotate it out

Challenger - You`ll wish You Hadn`t

Offline HP_Cuda

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #2 on: September 13, 2013 - 01:23:21 PM »

heh they better be gold plated donuts otherwise you are on your own!

 :popcorn:
1970 Cuda Clone 440 4 speed - sublime green
1970 Cuda 383 4 speed - yellow - SOLD

Offline Moneypit440

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #3 on: September 17, 2013 - 06:33:28 PM »
The dome light has power all the time & a 2 contact bulb where the ground is connected either at the doors or headlamp switch so you should have power with a test light but it should not short when tested .
 

Chryco:  Here is what is happening with the dome light.  With the dome housing and bulb removed, socket hanging by the two wires, when I test it the pink wire (positive, I assume) is drawing power both at the back of the socket and at the bulb-contact point.   The yellow wire indicates no power.  When I connect the bulb, it does not light but both wires show power when I touch them at the back of the socket.  Should yellow be showing power once I add the bulb, or is the socket bad?
1970 Challenger R/T 440 Magnum/727 Torqueflite
1970 Cuda 383 Super Commando/A833 4-speed
2010 Challenger R/T Automatic w/Magnacharger/CAI/Catback Exhaust Upgrade

Offline Chryco Psycho

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #4 on: September 19, 2013 - 08:11:22 PM »
pink is power in , yellow is the ground circuit to the headlight switch & door switches , are the wires grounding in the socket behind the light contact plate ?

Challenger - You`ll wish You Hadn`t

Offline Moneypit440

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #5 on: September 27, 2013 - 07:15:51 PM »
pink is power in , yellow is the ground circuit to the headlight switch & door switches , are the wires grounding in the socket behind the light contact plate ?

Somewhat embarrassed to say I don't understand what "grounding in the socket behind..............." means.  All I know is pink lights up my tester with the door open, and when I put the bulb in both wires light the tester, but bulb doesn't work.  I am totally new to electrical.  I did notice that when I pulled carpet out of Chally, I replaced the shift console light bulb, and the new one only worked when the socket contacted metal.  When I just held it in the air, I got no light.  I am aware that things need to be grounded to metal to work right, but I never learned why.
1970 Challenger R/T 440 Magnum/727 Torqueflite
1970 Cuda 383 Super Commando/A833 4-speed
2010 Challenger R/T Automatic w/Magnacharger/CAI/Catback Exhaust Upgrade

Offline Chryco Psycho

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #6 on: September 27, 2013 - 11:32:29 PM »
think of it like plumbing , water is taken from the reservoir through the plumbing to the tap  & returned to the reservoir through the sewer , same with electrical power comes from the battery & has to be returned to the battery to complete the circuit .
 the bulb in the dome light has to have 2 contacts on the base often a single contact bulb is inserted there , so you have power in on the pink wire , the power goes to ground out through the yellow wire & will ground in any place ,the door switches or the headlight switch , any can provide the ground

Challenger - You`ll wish You Hadn`t

Offline Moneypit440

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Re: 70 Cuda - dome light, fender turn signals, tail lights, fog light questions
« Reply #7 on: September 30, 2013 - 11:16:37 PM »
think of it like plumbing , water is taken from the reservoir through the plumbing to the tap  & returned to the reservoir through the sewer , same with electrical power comes from the battery & has to be returned to the battery to complete the circuit .
 the bulb in the dome light has to have 2 contacts on the base often a single contact bulb is inserted there , so you have power in on the pink wire , the power goes to ground out through the yellow wire & will ground in any place ,the door switches or the headlight switch , any can provide the ground

Ok so when the bulb is in, door open, test light tells me power is flowing through both wires.  So shouldn't the bulb light up?
1970 Challenger R/T 440 Magnum/727 Torqueflite
1970 Cuda 383 Super Commando/A833 4-speed
2010 Challenger R/T Automatic w/Magnacharger/CAI/Catback Exhaust Upgrade

Offline Chryco Psycho

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yes & no , usually the voltage will be much lower on the yellow wire going to ground  after the resistance of the bulb , if both wires have full 12v power then the yellow wire may be connected to the wrong place therefore you have no ground , I assume you have the correct bulb with 2 contact points on the end ?

Challenger - You`ll wish You Hadn`t

Offline Moneypit440

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I do have the correct bulb.  I even pulled the working bulb from the Challenger and tried it, in addition to two new bulbs.
1970 Challenger R/T 440 Magnum/727 Torqueflite
1970 Cuda 383 Super Commando/A833 4-speed
2010 Challenger R/T Automatic w/Magnacharger/CAI/Catback Exhaust Upgrade