Headlights on, dash guages pegged.

[will]

When I turn my headlights on my guages peg all the way to the right. I also have a surge when the engine is run up in rpms, about 200 rpm bouncing back and forth every 10 seconds or so, nothing consistent. I'm lost, please help

[tatrick2me]

The voltage regulater on the back of the gauge panel has gone bad.

[nascarxx29]

Also make sure cluster is tight and well grounded

[A383Wing]

Also make sure cluster is tight and well grounded

yup...what he said

[resq302]

I bet something with the wiring is not right.  Turning the headlights on has no bearing on the instrument gauges.  Do the gauges do the same thing with the headlights off?  If so, I would check the voltage limiter like the previous posts suggested.  Do not run the car or even have the key turned on for that long if they are all doing that because you WILL fry all of your gauges.  A full 12 volts to a gauge that is set up to run on 5 volts is not good!

[nascarxx29]

This problem is described in the service manual.In the electrical section troubleshooting for the instrument cluster.Will try to scan the page

[nascarxx29]

Right from service manual ALL GAUGES READ HIGH "againist the peg" AFTER IGNITION SWITCH IS TURNED ON" faulty voltage limiter and cluster not properly ground to instrument panel  .

As key on is 12 volts and instrument voltage limiter convert to 5 volts for gauges.The dash cluster has to be grounded for limiter to work correctly.Turning on the headlight is the feed for the dash lights not a power source to gauges.But when things are not properly grounded.Things get crossed up.
Had a car beeped horn and wipers would start up.Electricity will choose a shorter path to any devise.When grounds are insufficient

[will]

The guages peg when the lights are turned on. This cluster was redone last year with a new voltage regulator installed in the cluster. I'm aware of the troubleshooting section, this seems to me that it wouldn't apply. Thanks so far.

[1970Moparmann]

Last year I had the same problem.  I had to replace the voltage regulator in the engine compartment.  Good to go.    

My car has a MSD unit in it also.

[A383Wing]

check all yer grounds...the strap at the engine to firewall...and the ground from cluster peg to it's body connection....

the gauges are getting power via the "no ground" issue....

replace the gauge regulator and make sure all ground connections are good.

I had an issue with my 66 last year....everything was fine until I stepped on the brake....then gauges would start to rise...long story short....the ground strap from the engine block to the firewall broke....actually, I broke it, but we won't go into how I did it

after I replaced said strap, all is well in electrical land again

[70charginglizard]

check all yer grounds...the strap at the engine to firewall...and the ground from cluster peg to it's body connection....

the gauges are getting power via the "no ground" issue....

replace the gauge regulator and make sure all ground connections are good.

I had an issue with my 66 last year....everything was fine until I stepped on the brake....then gauges would start to rise...long story short....the ground strap from the engine block to the firewall broke....actually, I broke it, but we won't go into how I did it

after I replaced said strap, all is well in electrical land again

[will]

grounds on the firewall and on the battery are connected, same result. I guess I'm going deeper once the rain stops. Got the fluke and I'm ready to roll, just need a break between the work and the weather. 6 12's and one day off a week makes for seldom troubleshooting. I'll post what I find, I may just run a separate ground directly to the cluster.

[doctor4766]

My gauges peaked out at one stage (although headlights were off) and I discovered that there is a ground strap soldered to the voltage regulator. It had come off. After soldering it back on all was good again.
I'd say there is something not quite wired right if switching on the lights is feeding 12v to the cluster "after" the regulator.

[will]

I just wish the car was here, I'd be out there now instead of on here. Kids accessories have taken over the garage, so the car migrated to my fathers house. It'll be furloughed once the rain stops.

[will]

Update: Removed the cluster today, didn't find anything amiss. Put a spade on the cluster, got new speed nuts for the cluster. Put a separate ground from the cluster to the dash frame. Same thing, guages peg with lights on. I'm at a loss. I'm ready to pull the cluster out and replace the harness.