Author Topic: 73 Challg gauges don't work  (Read 384 times)

Offline 340-FOUR- BARRELL

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73 Challg gauges don't work
« on: April 20, 2017 - 11:04:47 pm »
Bought a 73 Challenger last week. The head lamps, tail lights, horn, dome light, speedometer all work. The oil pressure gauge, water temp, ammeter, fuel gauge, tach, wipers, turn signals, don't work. The seller said the dash voltage regulator may need replacing. Where is the dash voltage regulator located? There are some electric connectors/plugs that are not being used under the dash...could this be the problem? Near left side of glove box (six spade connector), and next to steering column three plug connector not being used. Any suggestions, Thank You




Offline Lbs

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Re: 73 Challg gauges don't work
« Reply #1 on: April 20, 2017 - 11:24:03 pm »
The voltage limiter is on the backside of the gauges. Not sure if that's the problem but it makes sense. Somebody here will shed some light on it for you.


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Offline Beekeeper

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Re: 73 Challg gauges don't work
« Reply #2 on: April 20, 2017 - 11:53:06 pm »
Don't ignore the possibility that there are several unrelated problems occurring at the same time. Since you just got the car, some of these things could have failed over time separately. If you're lucky, a simple fix will cure everything.

I'd start by verifying that all ground wires in and around the dash and engine compartment are properly connected.

I'm thinking gauges are all one problem. You can see from lbs's pic that the gauges which are not working are all fed from the same source so maybe that voltage regulator or that wire cluster is the issue on the gauges.

I'm wondering if your turn signals are something else. You said tail lights work but you didn't say if brake lights work. The turn signals use the same element as the brake light so if brake lights work, you can narrow that down to the column or dash wiring. I would think your turn signals would normally work even if you removed the gauge cluster. Check the wiring looms coming out of the column...people cut and splice and disconnect those all the time.

It's not unusual for the tach to fail over time. Could also be that the feed wire for the tach on the coil is not connected properly.

On the wipers, possible a switch went bad or the wiper motor failed.

Did the seller say if all these things failed on the same day or one by one. I'm gonna guess one by one.


Offline Lbs

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Re: 73 Challg gauges don't work
« Reply #3 on: April 21, 2017 - 12:37:40 am »
I see from your other post that you are in the Bay Area which is where I am also. I'm in Pacheco which between Martinez and pleasant hill. If you would like some help with it you can PM me or their is a cruise night tomorrow at Kinders in Concord off highway 4. Mopar Jack might be there and he is a pretty sharp guy and usually willing to help.


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Offline 340-FOUR- BARRELL

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Re: 73 Challg gauges don't work
« Reply #4 on: April 21, 2017 - 03:12:39 am »
Beekeeper the driver side brake light works when the brakes are applied. Passenger side brake light does not come on. Hmmmm I will check all the ground connection, tach to coil wire, and the voltage limiter on the back side of the gauges.

Lbs, I will try to make Kinder's in Concord this Friday nite. When is a good time to be there?

Offline xtopfuel

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Re: 73 Challg gauges don't work
« Reply #5 on: April 21, 2017 - 06:41:57 am »
LOL I am having same issues

Offline Beekeeper

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Re: 73 Challg gauges don't work
« Reply #6 on: April 21, 2017 - 09:39:25 am »
Beekeeper the driver side brake light works when the brakes are applied. Passenger side brake light does not come on. Hmmmm I will check all the ground connection, tach to coil wire, and the voltage limiter on the back side of the gauges.

Lbs, I will try to make Kinder's in Concord this Friday nite. When is a good time to be there?

I am no expert when it comes to electrical issues but it's been my experience that older cars like ours deteriorate fast and require tons of maintenance which many owners don't have time for. Hopefully someone will chime in with a simple solution but I think you're gonna have tackle them one by one. I'd pick the thing that bothers you most...for me it would be the gauges. A pain yes but I'm certain that the failure of the three gauges is due to one cause so if you track it down, you should be able to fix three of them all at once.

Offline mopar jack

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Re: 73 Challg gauges don't work
« Reply #7 on: April 21, 2017 - 10:00:11 am »
The cruise night gathering starts around 5:00  and ends around 7:00. Hope to see you there.

Offline chargerdon

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Re: 73 Challg gauges don't work
« Reply #8 on: April 21, 2017 - 02:20:30 pm »
Just my two cents...   The voltage regulator only controls the gas, temp and oil pressure.   The amp meter is NOT part of the voltage regulator.   A lot of guys disconnect the amp meter for fear of melting or catching on fire.   

Gauges have noting to do with the brake lights.   

So, you do have multiple issues.

Offline 340-FOUR- BARRELL

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Re: 73 Challg gauges don't work
« Reply #9 on: May 04, 2017 - 12:29:24 pm »
Mopar jack and LBS, Thanks for telling me about Concord Cruise night. Enjoyed  meeting the two of you. Surprised to see such a large turnout of quality collector cars...and several classic MOPARS. The next day, I tore the skin off the back of my fingers on my right hand, fresh meat that looked like hamburger.  My fingers are still in splints. The bad part is I just acquired the '73 Challenger and I can't do a complete tune up on it. I have new MSD 8mm wires, plugs, cap, air filter, etc. Haven't bee able to tackle the gauge wiring issues either. :pullinghair: I'm basically on the forum's injured reserve list. LOL

Offline Lbs

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Re: 73 Challg gauges don't work
« Reply #10 on: May 04, 2017 - 08:47:54 pm »
Mopar jack and LBS, Thanks for telling me about Concord Cruise night. Enjoyed  meeting the two of you. Surprised to see such a large turnout of quality collector cars...and several classic MOPARS. The next day, I tore the skin off the back of my fingers on my right hand, fresh meat that looked like hamburger.  My fingers are still in splints. The bad part is I just acquired the '73 Challenger and I can't do a complete tune up on it. I have new MSD 8mm wires, plugs, cap, air filter, etc. Haven't bee able to tackle the gauge wiring issues either. :pullinghair: I'm basically on the forum's injured reserve list. LOL
That is certainly not very good news. What happened? Did the car bite you or did life just happen? Any idea how much longer you'll be on the DL?
It was great meeting you too. Hope it won't be too long before you can get after that wiring problem again. Hope to see you on Fridays again soon.


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Offline jimynick

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Re: 73 Challg gauges don't work
« Reply #11 on: May 07, 2017 - 10:35:46 pm »
A probe type test light and a alligator-clipped jumper wire would be two useful things to have here. If you've got one taillight working, but not the other, I'd pull the bulb and probe for power and then try grounding the bulb housing with the jumper and see if it lights. It's basically a process of checking the schematics and going through the system looking for power and/or where it starts to show them. good luck   :cheers:

Offline xtopfuel

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Re: 73 Challg gauges don't work
« Reply #12 on: May 08, 2017 - 07:07:56 am »
I updated the fuse box thread as I fixed mine Thursday, we removed the bulkhead and cleaned and lubed, put everything back together and they work