1970 wiring on 1972 fuse block

[Old B5]

I have a 1970 challenger that came with a standard dash. I am using the original wiring except i am using a 1972 fuse block and instrument cluster wiring harness. Only gauge that works is voltage. I also can't get the brake lights to work. The tail lights work but not the brake lights. I have replaced the brake switch on the brake pedal.

What should be done when switching to a different fuse block?

Thanks for any help. I hate wiring/electrical problems more than anything.

 

[moparleo]

Are you also using a standard gauge cluster with the new harness ? Did you also change the engine/ignition harness as well. ?
Reason for the mismatch? Engine change ?
You really didn't give much detailed info.

 

[Chryco Psycho]

Likely the brake light problem is in the turn signal switch , the power to the brake lights is interupted on one side when the turn signal is activated .
You need to compare the wiring at the fuse block for the 2 years & may have to change the position of some of the wires in the fuse block .

 

[Old B5]

Using a Rally Gauge cluster. Engine harness is from original 318 and now 340 in car. Changed wire harness when switching to rally gauges.

 

[Challenger RTA]

Volt Gauge or amp gauge? I think you mean amp gauge. they are wired different. The above advice needs to followed.Below is how it needs to be wired like the diagram. .You can use a standard harness.but you must study and know what you are doing when changing connections locations.

 

[moparleo]

So the harness is original to the Rally gauge cluster ? What year cluster ? Is it also 72 ? 70-71 are different from 72-74.
Items like seat belt buzzers, 2 or 3 speed wipers. a/c connections and others. electronic ignition or points. It matters for the tach to work.
The different clusters have different connections. The engine side harness needs to match the passenger side.

 

[Old B5]

The harness is from a 1973. Engine harness and tail light harness are original 1970

 

[Challenger RTA]

Behind the drivers kick panel is the connector for the rear body.just in case you didn't know. in general there the same.