I am looking for information on changing out, or at least getting to, the heater for a '99 Olds Silhouette. I was told by the dealer’s service dept. the core was plugged with leaf debris and packed solid. They said the water side worked OK and the dampers worked OK. I have been looking for a drawing showing the installation but can’t find one. I hope you can help!
The Autozone web site has some repair information available so try that. You can go to Alldata.com and purchase information and also get free information at the public library.
Does this car not have air conditioning? How did the leaves get bast the evaporator and clog the heater core. The former is always first in the intake air flow. What are your symptoms, reduced air flow?
I have a 2000 so the systems should be the same.
Through the glove box is where you’ll find two cabin filters.
The are directly below the outside fresh air vents and are in direct line with the heater motor blower.
(If the outside plastic vent screen is eroded, and may well be, check around the wrecking yards for a used one)
Clean or change these and stick a flexible vacuum hose down the duct work as far as it will go. That should work.