Can't figure out why my second (left) axis doesn't show up on the final plot

I've been trying to understand what's wrong with the below code as it used to work just fine for me. So, the idea was to put 2 different plots on one with 2 different Y-axes. If parts of the code are taken separately they produced 2 different plots with all necessary elements in the picture. However, if to run the whole code ( including its final part that combines 2 plots), my left axis doesn't show up whatsoever. Would appreciate if someone takes a look at the code and gives an idea what might be wrong. Thank you.

P7 <- structure(list(date = structure(c(2014, 2014.25, 2014.5, 2014.75, 
2015, 2015.25, 2015.5, 2015.75, 2016, 2016.25, 2016.5, 2016.75, 
2017, 2017.25, 2017.5, 2017.75, 2018), class = "yearqtr"), ODKR = c(2.092768404, 
1.587425058, 0.904469551, 0.548433616, -1.449442893, -1.843531888, 
-1.089236583, -1.275385463, -1.973940688, -1.670021115, -0.981188858, 
-0.194177492, -0.676053884, -0.293227813, 1.042061349, 1.898574333, 
2.184102398), NIAFS = c(-1.950890872, -1.957013529, -1.455253067, 
-2.599998653, -3.540605757, -3.035047278, -2.53037091, -2.487742291, 
-2.618652384, -2.552271705, -2.001632782, -1.138414183, -0.744018494, 
0.180241462, 1.607739574, 2.425280424, 2.588187372), NPFSFC = c(-2.000890872, 
-1.423063529, -0.678303067, -1.219348653, -1.892455757, -1.392847278, 
-1.31052091, -1.826792291, -2.122952384, -1.767921705, -0.933382782, 
-0.115564183, 0.138731506, 0.130991462, 0.265439574, 0.233830424, 
0.185537372), RAGEDS = c(105.9026783, 82.31456143, 79.92934972, 
55.20912827, 45.64779976, 40.33413521, 46.06328256, 53.96840203, 
52.23471724, 58.03816223, 57.46826338, 80.03298941, 82.46083813, 
83.16642902, 116.6794117, 126.9070905, 122.0783339), RASTGEDS = c(47.31076477, 
42.66400908, 43.51889476, 45.13006291, 39.45547991, 36.57969248, 
38.90591583, 41.09343372, 36.40754691, 37.05760134, 38.19802909, 
43.69801957, 46.40378222, 49.22426229, 66.43377886, 74.38301618, 
75.25486848)), .Names = c("date", "ODKR", "NIAFS", "NPFSFC", 
"RAGEDS", "RASTGEDS"), row.names = c(NA, -17L), class = "data.frame")


P7_lines <- subset.data.frame(P7, select = c("date", "ODKR", "NIAFS", "NPFSFC"), date >='2014 Q1')
P7_bars <- subset.data.frame(P7, select = c("date", "RAGEDS", "RASTGEDS"), date >='2014 Q1')


P7_bars_melt <- melt(P7_bars, id.vars = "date", measure.vars = c("RAGEDS", "RASTGEDS"))
P7_lines_melt <- melt(P7_lines, id.vars = "date", measure.vars = c("ODKR", "NIAFS", "NPFSFC")) #transforming data from a wide to long format

P7_bars_chart <- ggplot(P7_bars_melt, aes(x = date, y = value, fill = variable)) +  

  scale_x_yearqtr(breaks = seq(from = min(P7_bars$date, na.rm = T), to = max(P7_bars$date, na.rm = T), by=0.25), format="Q%q %Y", expand=c(0,0)) +
  scale_y_continuous(limits = c(0,135), breaks = seq(5,135,10), expand = c(0,0), position = "right") +

  coord_cartesian(ylim = c(35, 135)) + #adjust the visible area

  xlab ("") +
  ylab ("") +

  geom_bar( 
        aes(
          ),
          stat = "identity",
          position=position_dodge()) +

  scale_fill_manual(
    guide = "legend", 
    name = NULL, 
    breaks= c("RAGEDS", "RASTGEDS"), 
    labels= c('Резерв. активы/обслуживание валового \n внешн. долга, % (правая ось)', 'Резервн. активы/краткосрочный \n валовый внешний долг, % (правая ось)'),
    values = c('#4477AA', '#117733')) + 

  theme(axis.text.x = element_text(angle = 90, vjust = .5, size = 5, colour = "black"),
        axis.text.y = element_text(size = 5, colour = "black"),
        #panel.grid.minor.x = element_line(colour = "#EDEDED", linetype = 2),
           axis.line.y = element_line(colour= NA), 
        axis.line.x = element_line(colour= "#ABABAB", vjust = .5),

        panel.grid.major.y = element_blank(), #element_line(colour = "#EDEDED", linetype = 2, size = .3),
        panel.grid.minor.y = element_blank(),
        panel.grid.major.x = element_blank(),
        panel.grid.minor = element_blank(),
        panel.background = element_blank(),

        axis.ticks.length = unit(0,"cm"),
        legend.position = "bottom",
        legend.direction = "vertical",
        legend.spacing.x = unit(-.2,"cm"),
        legend.key = element_blank(),
        legend.key.height = unit(.5, "cm"),
        legend.text = element_text(size = 5),
        legend.box.margin = unit (c(-7,1,1,1), "mm"),
        legend.background = element_rect(fill = "transparent", colour = NA),
        plot.margin = unit (c(1,0,0,0), "mm")) 
P7_bars_chart


P7_lines_chart <- ggplot(data = P7_lines_melt, aes (x = date, y= value, colour = variable))+

  scale_x_yearqtr(breaks = seq(from = min(P7$date), to = max(P7$date), by=0.25), format="Q%q %Y", expand=c(0,0)) +
  scale_y_continuous(limits = c(-4,3), breaks = seq(-4,3,1), expand = c(0,0), position = "left") + 
  xlab ("") +
  ylab ("") +
  geom_line(size = 1, stat = 'identity')+ 
    scale_colour_manual (
    guide = "legend", 
    name = NULL,
    breaks = c("ODKR", "NIAFS", "NPFSFC"), 
    labels = c("Чист. внеш. позиция ОДКР, млрд. долл. США (левая ось)", "Чист. иностр. активы финсектора,  млрд. доллл. США (левая ось)", "Чист. позиция финсектора в иностр. валюте, млрд. долл. США (левая ось)"), 
    values = c("#117733", "#DDCC77", "#CC6677"))+
  labs(x=NULL, y=NULL)+
  theme(axis.text.x = element_text(angle = 90, vjust = .5, size = 5, colour = "black"),
        axis.text.y = element_text(size = 5, colour = "black"),
        axis.line.y = element_line(colour=NA), 
        axis.ticks.length = unit(0,"cm"),
        #panel.grid.minor.x = element_line(colour = "#EDEDED", linetype = 2),
        panel.grid.major.y = element_blank(), #element_line(colour = "#EDEDED", linetype = 2, size = .3),
        panel.grid.minor.y = element_blank(),
        panel.grid.major.x = element_blank(),
        panel.grid.minor = element_blank(),
        panel.background = element_blank(),

        legend.position = "bottom",
        legend.direction = "vertical",
        legend.spacing.x = unit(-.2,"cm"),
        legend.key = element_blank(),
        legend.key.height = unit(.2, "cm"),
        legend.text = element_text(size = 5),
        legend.box.margin = unit (c(-7,1,1,1), "mm"),
        legend.background = element_rect(fill = "transparent", colour = NA),
        plot.margin = unit (c(1,0,0,0), "mm"))
#plot.title = element_text(family = "Franklin Gothic Book", face = 'bold', size = 10)

P7_lines_chart


g1 <- ggplot_gtable(ggplot_build(P7_bars_chart))
g2 <- ggplot_gtable(ggplot_build(P7_lines_chart))


pp <- c(subset(g1$layout, name == "panel", se = t:r))
g <- gtable_add_grob(g1, g2$grobs[[which(g2$layout$name == "panel")]], pp$t,
                     pp$l, pp$b, pp$l)
# axis tweaks
ia <- which(g2$layout$name == "axis-r")
ga <- g2$grobs[[ia]]
ax <- ga$children[[2]]
ax$widths <- rev(ax$widths)
ax$grobs <- rev(ax$grobs)

g <- gtable_add_cols(g, g2$widths[g2$layout[ia, ]$l], length(g$widths) - 1)
g <- gtable_add_grob(g, ax, pp$t, length(g$widths) - 1, pp$b)


leg1 <- g1$grobs[[which(g1$layout$name == "guide-box")]]
leg2 <- g2$grobs[[which(g2$layout$name == "guide-box")]]

leg = gtable:::cbind_gtable(leg1, leg2, "first")            
leg$widths[5:6] = unit(0, "cm")

g$grobs[[which(g$layout$name == "guide-box")]] <- 
  gtable:::cbind_gtable(leg1, leg2, "first")
grid.draw(g)

plot(g)
dev.off()

This is what I've got all the time:

enter image description here

Data on the R session:

R version 3.4.4 (2018-03-15)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS High Sierra 10.13.5

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.4/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] scales_0.5.0    gtable_0.2.0    Cairo_1.5-9     openxlsx_4.1.0  extrafont_0.17  zoo_1.8-2       reshape2_1.4.3  forcats_0.3.0  
 [9] stringr_1.3.0   dplyr_0.7.4     purrr_0.2.4     readr_1.1.1     tidyr_0.8.0     tibble_1.4.2    ggplot2_2.2.1   tidyverse_1.2.1