Dash Lights flicker

[USAFLong]

If i turn the headlights on the dash lights are fine as long as I'm not driving. Once I start driving the dash lights start to flicker, including the hi-beam and turn signal lights. The outside lights are fine and the cd player isn't dimming or losing power. I believe the ground needs a better connection for the dash lights. I have no idea where the wiring for the dash/gauge lights are.

Can anyone point me in the right direction so I can clean or make a new ground?

[Hobcobble]

I have no idea where the wiring for the dash/gauge lights are.

Can anyone point me in the right direction so I can clean or make a new ground?

The wiring for the instrument panel is behind the instrument panel.
On the '70 panel, there should be four screws that need to be removed. Once
you're behind it, take a look at this diagram.... see if it helps....
http://www.sweptline.com/tech/70wire.jpg
Your panel lights are tied in with your head lamp switch, low/high beam switch and
fuse block. The rheostat on the head lamp switch can sometimes cause the problem
you're experiencing.... they can be purchased new at your local NAPA if it turns out
to be the problem.
John

[USAFLong]

If I replace the headlight switch as a whole, is the rheostat included? I can turn the dimmer to the left and before it clicks for the dome light all the lights go out. I don't think thats normal.

[Trailmaster]

If I replace the headlight switch as a whole, is the rheostat included? I can turn the dimmer to the left and before it clicks for the dome light all the lights go out. I don't think thats normal.

The rheostat is part of the headlamp switch, if it's bad you can take it out and replace it but if you can find a new headlamp switch that is a much better option. Most Mopars I've seen do kill the instrument lights when the dome light is on, I know the Duster and all my Lifestyle trucks have it that way. I would go check my 70 to be sure but right now the battery is disconnected while the trans is out, but I'm sure it's that way also.
Does the fuel or temp guage fluctuate when the lights flicker? If so that would narrow it down to instrument panel ground, but if the ground loss is a real quick momentary thing it might not be long enough in duration to affect the guages. I haven't had the instrument cluster out of my 70, but most I've seen ground through the screws that mount the cluster, it might be that a ground strap needs added.

[OrangeRoughy]

Hobcobble,

How far back does NAPA go with these headlight switches? My '64 works the head and parking lights fine, but no dash lights. Having several mopars I know the rheostat is likely the reason.

[Trailmaster]

Ain't meaning to cut in on somebody here, but I checked O'Reilly and they go back to 63 on the switch.

http://shop.oreillyauto.com/ProductDeta ... 08&PTSet=A

[Hobcobble]

Hobcobble,

How far back does NAPA go with these headlight switches? My '64 works the head and parking lights fine, but no dash lights. Having several mopars I know the rheostat is likely the reason.

I looked this up for a '64.
http://www.napaonline.com/MasterPages/N ... ght+Switch
There is another one listed that is abut $10 less too....
http://www.napaonline.com/MasterPages/N ... ght+Switch
John

[OrangeRoughy]

Excellent John, Thanks!

I'm slooowly getting one electrical item fixed at a time it seems. Now this is on my list!

[USAFLong]

How do you get the light switch out of the dash? I'm not sure how to remove it so I can replace it.

[Hobcobble]

How do you get the light switch out of the dash? I'm not sure how to remove it so I can replace it.

You have to reach up behind the dash and find a small "button" on the
housing of the switch. When you locate this button, push it in and slowly
pull the switch knob/shaft out from the front of the switch housing.
Remove the collar nut and the switch will then be able to be pulled
out from behind and un-clipped from the wiring harness.
John

[USAFLong]

Last night I put a new ignition switch and new lock cylinder in the truck. Much tighter and no slop. Mine must have been original because my key said Chrysler Corporation on it.

I then pulled out the gauge cluster and saw a metal wire screwed into the back of the housing. I assumed this was a ground. It was a white wire but it was grounding to the metal housing. I took some 12 gauge and some ring terminals and made a ground wire that went from there to the bottom of the dash support. Then I saw a common black ground running from the gas gauge to the temp gauge and oil pressure gauge. I made a jumper from the ground on the gas gauge to the ground on the ammeter because that is a thick @#% ground coming in from somewhere. I noticed when I connected that, my turn signals would work with the key off. Weird.

Then I looked down at the high beam switch on the floor. It had I think 4 wires. Three coming out of the switch and one with a round terminal just hanging there. It was a thick white wire like what was behind the gauges. I took one of the screws out of the mount for the high beam switch and grounded that white wire.

No sparking, nothing. Thought I was good to go. So I put it all back together and fire up the truck. Get going down the road and I'm happy that my lights don't flicker anymore. I go to turn on the heater and now the damn blower motor won't run. Also when I shut the truck off, the display clock on my CD player won't turn off.

I'm going to disconnect the jumper from the gas gauge to the ammeter ground and see if that fixes it. Also noticed my temp gauge shot sky high and didn't come back down. Gas gauge quit working a few months ago.

I'm going to start saving up for a set of autometer gauges and make my own gauge panel because these factory gauges are junk and I'd rather wire up all the new gauges through a fused power block so I know they will work.

[USAFLong]

Well apparently the wire I thought was the common ground connecting all the gauges was common power. Who the hell uses black for power???? I disconnected my jumper and everything seems to work now and the heater motor blows again (but it quits randomly.... that's the next project I'll tackle is cleaning the grounds and maybe running a relay to the switch to draw power right from the battery).

The only odd thing is the temp gauge used to work but when the lights were on it'd peg out. Now the lights no longer flicker but the temp gauge pegs.

I still want to make a custom gauge panel for this truck. I'm sick of messing with these old gauges. The only ones that work are the speedometer and the ammeter. I have an aftermarket tach on the steering column and an aftermarket oil temp gauge by my knee. Thats really all I need to know. I calculate the gas average and then just watch the odometer and fill it up every 180-200 miles.

Also put 420 lbs of sand bags in the bed so hopefully I get around in the snow better.

[Hobcobble]

Well apparently the wire I thought was the common ground connecting all the gauges was common power. Who the hell uses black for power???? I disconnected my jumper and everything seems to work now and the heater motor blows again (but it quits randomly.... that's the next project I'll tackle is cleaning the grounds and maybe running a relay to the switch to draw power right from the battery).

The only odd thing is the temp gauge used to work but when the lights were on it'd peg out. Now the lights no longer flicker but the temp gauge pegs.

I still want to make a custom gauge panel for this truck. I'm sick of messing with these old gauges. The only ones that work are the speedometer and the ammeter. I have an aftermarket tach on the steering column and an aftermarket oil temp gauge by my knee. Thats really all I need to know. I calculate the gas average and then just watch the odometer and fill it up every 180-200 miles.

Also put 420 lbs of sand bags in the bed so hopefully I get around in the snow better.

I'm wondering about the condition of your voltage limiter? Here's some
information regarding limiters at the link:
http://imageevent.com/jeffc/techstuff2e ... landheater

Have you compared your harness with a schematic to make sure everything
is as it should be? Many will tell you that the factory gauges are very reliable.
Over the years... folks add or take away electrical devices and the original
harness winds up getting "pruned". Another common problem is poor ground
wire contacts. Before you officially "condemn" your original loop.... you might
want to give it a thorough inspection.

Did you get your light switch out??
John

[Jeffc]

Well apparently the wire I thought was the common ground connecting all the gauges was common power. Who the hell uses black for power???? I disconnected my jumper and everything seems to work now and the heater motor blows again (but it quits randomly.... that's the next project I'll tackle is cleaning the grounds and maybe running a relay to the switch to draw power right from the battery).

The only odd thing is the temp gauge used to work but when the lights were on it'd peg out. Now the lights no longer flicker but the temp gauge pegs.

I still want to make a custom gauge panel for this truck. I'm sick of messing with these old gauges. The only ones that work are the speedometer and the ammeter. I have an aftermarket tach on the steering column and an aftermarket oil temp gauge by my knee. Thats really all I need to know. I calculate the gas average and then just watch the odometer and fill it up every 180-200 miles.

Also put 420 lbs of sand bags in the bed so hopefully I get around in the snow better.

I'm wondering about the condition of your voltage limiter? Here's some
information regarding limiters at the link:
http://imageevent.com/jeffc/techstuff2e ... landheater

Have you compared your harness with a schematic to make sure everything
is as it should be? Many will tell you that the factory gauges are very reliable.
Over the years... folks add or take away electrical devices and the original
harness winds up getting "pruned". Another common problem is poor ground
wire contacts. Before you officially "condemn" your original loop.... you might
want to give it a thorough inspection.

Did you get your light switch out??
John

John is correct, you need a basic understanding of what your working on before plugging
in "whatever" and trying differant things, thus the frustration.....however, the damage may be already done....
You may have "stressed" the voltage limiter (voltage limiter is a voltage regulator built into the fuel guage that keeps the voltage at around 5 to 6 volts so the fuel and temp gauges do not cook)- thus the pegged temp gauge---- failed gas guage may be a falty fuel tank sender or a sunk float and gauge itself "may have been" ok.......The jumper wire between the fuel gauge and temp gauge that you think is black is a very dark blue, or should be...
Read though this viewtopic.php?f=21&t=21475
My post cover most of the basic test here.... and link to my page John posted should help also were the guages are covered.....

Headlight grounds are at the light buckets, white wire attached to the sheet metal near the headlight buckets, remove any other wires you may have added, clean ground points at the
headlights...... I like to ground the negitive battery ground (buy a cable with the extra wire)
to the core support (front sheet metal). You may also find a new cable between the engine
and fire wall will help if it has not been replaced in the last few years...... cleaning all ground points may also help.....

[USAFLong]

The fuel guage quit with a full tank in the truck, and it just dropped to E so I doubt its the float sticking. As long as I have dash lights and a speedometer I'm fine. I have an aftermarket tach and oil pressure so I can get by until I do the new gauge panel with autometer gauges. Then I'll run all new power and grounds to the gauges so I know they will work. And then I'll find out for sure if my tank sender is bad. If it is, it'll be one more reason to remove the in cab tank and go with a fuel cell in or under the bed. I want to be able to put stuff behind the seat anyhow. Actually I think I'm going to go to the junk yard and find a bench seat that has an arm rest and that folds, and then mount that in my truch. My original seat is freshly re-upholstered so maybe I can sell it for some money?

[Jeffc]

The fuel guage quit with a full tank in the truck, and it just dropped to E so I doubt its the float sticking. ?

Easy to test the fuel gauge, so why not? with power hooked up just ground the sender wire at the tank, if gauge pegs after a few seconds the guage is good........and you have a bad sender or sunk float......

[blaine2morrow]

Can anyone i here help..

I peviously had my gauge cluster working.. all but speedo.. so I swapped it out for another speedo.. but I put a wire (WHITE) where I thought it went it fried another wire under my hood.. and the truck wud not start..

So I replaced the wire and got her runnig..

Then I got more intimate with the blueprint..to make sure eveything is where it is suppose to be.. and it is.. all but the WHITE wire which the blueprint says is the ground but does not show where on the back of the cluster it goes..

does anyone know..??

[kurt]

I looked at my 1966 gauge cluster which I pulled with all the wiring attached. It has no ground wire but the bulbs do gnd through the cluster enclosure. I probably shouldn't answer because I don't know but I would guess the wire just screws to the enclosure.

[nytemuvr]

I looked at my 1966 gauge cluster which I pulled with all the wiring attached. It has no ground wire but the bulbs do gnd through the cluster enclosure. I probably shouldn't answer because I don't know but I would guess the wire just screws to the enclosure.

My '68 has a white ground wire from the fusebox to the bolt holding the fusebox to the steering column, but '68 is one-year wiring.

[blaine2morrow]

So you are saying the white wire is attached to the same screws which holds the cluster in.. if I post a pice would you be able to provide a better description... p.s. im driving a 1969 d200