70 Charger cuts out at idle when brake is pressed when hot

[Bob T]

Howdy , a mate of mine has a problem with his car cutting out at idle when hot when the brake is pressed, when it has a few revs on above idle it is fine. when its cold its fine

All good until it gets hot. Then when the lights are on and sitting in traffic with motor idling is is ok until you have it in gear and foot on the brake. Then it cuts out. Its as if the alt cant keep up at low revs and power cuts out. Even when in gear idling and put your foot on the break the radio cuts out. Any ideas ? Has a 70Amp Alt on it. Only does it when hot, not when cold.

Any help appreciated, Thanks

[nascarxx29]

   On one hand syptoms sound Carb issue like a vacuum leak.As it wont idle underload.Or carb dropping to much fuel at idle killing it .But mopars rapidly discharge at idle its inherit .Do you have electronic ignition or regular points.What comes to mind when stepping or brakes the brake light electrical load whats the amp gauge showing.Or if you have a power brake booster loosing vacuum.Causing it to stall stepping on the brakes .Just a few thoughts anybody else had these issues

[Bob T]

Its electronic ignition, stock type. The booster has been off recently for a rekit at a brake recond shop and the carb was new out of the box about a year ago. I dont know what the amp guage is reading at that instant.
But in saying that, I think you have raised a good point with vac leak, we'll chase that.
Thanks a lot 

[rs70chgrrt]

My 70 used to do that at night with the headlights on. I found that the voltage going to the ignition system(electronic NOT points) was going to low when I depressed the brakes. I installed a mini alternator from a Chrysler minivan (135 amp) I think. Had to rewire the system from the alternator to the battery because of the increased amperage. Lights are bright and don't dim at all at stops and the stalling went away as well.  Hope this was helpful to you.

[AKcharger]

I had the EXACT same problem and it's increadibly frustrating! I did the "magic headlight upgrade" and the problem is solved. The headlight mod is a MUST DO regardless if the car has a cut out problem or not! Lights nice and bright and a lot safer with less current flowing through the dash http://www.dodgecharger.com/forum/index.php/topic,168.125.html

[charger Downunder]

Had a smiler problem many years ago when i touched the brake.
I would check and clean the battery earth. Plus have a look at the two long  plastic wire joiners under the dash coming from the steering column see if there is any browning on the joins. Its best to pull them apart clean and put back together.