sanger sequencing data depends on quality of the amplification. as for individual peak the height depends on, first the nucleotide (each associated dye has different emission strength, and second the number of the fragments containing and ending by this base will be amplified and sequenced.
now, in your case since you got a variant, you will also have to consider the overlapping of the 2 dye emission lengths AND the proportion of C and A in the sequence of your sample (frequency of the variant).
sanger sequencing data depends on quality of the amplification. as for individual peak the height depends on, first the nucleotide (each associated dye has different emission strength, and second the number of the fragments containing and ending by this base will be amplified and sequenced.
now, in your case since you got a variant, you will also have to consider the overlapping of the 2 dye emission lengths AND the proportion of C and A in the sequence of your sample (frequency of the variant).
Frederic's answer is very good. I've attached a brief guide from our core facility that links sequencing problems with associated electropherograms. It has helped me troubleshoot problems with my own Sanger sequencing projects.