Looking rearward, the cowl drain can be inspected. This & the one on the driver's side often hold rotting leaves which can rust the body & cause odors in the HVAC system. This one was fairly clean because a squirrel had used it to get inside the blower for the winter, and I already fixed that mess. I haven't checked the other side.
The silver insulation on the R side of the pic shields the evaporator box from the R exhaust manifold, and hides the heater core & condensate drain, which barely protrudes thru the firewall. The drain drips onto the frame below, which is why the frame is rusty there. The wetness on it right now is penetrating oil I sprayed on the exhaust flange. I didn't fix it on this truck, but the evaporator insulation can be replaced with a more-robust modern material, like this:
The yellow plate above the insulation is the blower resistor; notorious for setting leaves in the box on fire, and for defaulting to hi-speed only when its thermal fuse burns out. The leaf fire can be prevented by 1) cleaning the cowl & its drains regularly, &/or 2) adding screen inside the cowl to keep the leaves from entering the blower intake, &/or 3) adding foam to seal the wiper valance ('87-96 only) so leaves can't enter the cowl.
.
.
.
The black bar above the cowl drain is the lug wrench. There should be a hard plastic (natural nylon) grommet in the mounting tab on the fender to prevent noise. It can be replaced by slitting a small rubber vacuum hose to cover the metal edge.
![03cowldrain.jpg Looking rearward, the cowl drain can be inspected. This & the one on the driver's side often hold rotting leaves which can rust the body & cause odors in the HVAC system. This one was fairly clean because a squirrel had used it to get inside the blower for the winter, and I already fixed that mess. I haven't checked the other side.
[url=http://www.supermotors.net/registry/media/901904][img]http://www.supermotors.net/getfile/901904/thumbnail/cowldrainpacked.jpg[/img][/url]
The silver insulation on the R side of the pic shields the evaporator box from the R exhaust manifold, and hides the heater core & condensate drain, which barely protrudes thru the firewall. The drain drips onto the frame below, which is why the frame is rusty there. The wetness on it right now is penetrating oil I sprayed on the exhaust flange. I didn't fix it on this truck, but the evaporator insulation can be replaced with a more-robust modern material, like this:
[url=http://www.supermotors.net/registry/media/964781][img]http://www.supermotors.net/getfile/964781/thumbnail/evapins.jpg[/img][/url]
The yellow plate above the insulation is the blower resistor; notorious for setting leaves in the box on fire, and for defaulting to hi-speed only when its thermal fuse burns out. The leaf fire can be prevented by 1) cleaning the cowl & its drains regularly, &/or 2) adding screen inside the cowl to keep the leaves from entering the blower intake, &/or 3) adding foam to seal the wiper valance ('87-96 only) so leaves can't enter the cowl.
[url=http://www.supermotors.net/registry/media/955476][img]http://www.supermotors.net/getfile/955476/thumbnail/22screeq.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/947911][img]http://www.supermotors.net/getfile/947911/thumbnail/22screen.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/947910][img]http://www.supermotors.net/getfile/947910/thumbnail/22screep.jpg[/img][/url] . [url=http://www.supermotors.net/registry/media/958829][img]http://www.supermotors.net/getfile/958829/thumbnail/22wipervalseal.jpg[/img][/url]
The black bar above the cowl drain is the lug wrench. There should be a hard plastic (natural nylon) grommet in the mounting tab on the fender to prevent noise. It can be replaced by slitting a small rubber vacuum hose to cover the metal edge.](https://www.supermotors.net/getfile/770503/fullsize/03cowldrain.jpg)