Front Lights and Gauges Flickering

When I turn on the hazard lights, turning signal lights, or hit the brake pedal, the front lights and gauges of my Toyota truck flicker. Also the radio turns off for a second making a pop thru the speakers.

Car description: Toyota truck 4x2 extra cab, stick shift 5 speed, 1995, 4 cylinder, 2.4, 116 horse power, 112,000 miles.

I have taken the truck to 2 different Toyota dealers and they have not fixed the problem.  They say that the car is fine. Alternator, battery, and charge is just fine.

I have replaced the negative cable that goes to the battery, and have connected the radio direct to the battery to avoid the pop on the radio thru the speakers, replacing the negative cable cured the problem for a few days only.

Definitely there is something wrong where the lights connect.  Perhaps the relay is bad?

Thanks a millions in advance for your help.

I would take bets on the main ground for the dash being loose, or one of the main grounds for the lighting circuits.  Also check the ground for the lighting relays.

I'll do that.  As a matter in fact, I'll install an additional ground cable to all of them just to see if the problem gets resolved.

Can you guys provide me with a diagram please? or point me to the right direction?  Thanks.

Toyota truck extra cab, 4 cyl, 2.4, 1995. It is not the tacoma model, it is the model before the first tacoma.