Interpretation ID: nht72-6.59

DATE: 05/05/72 EST

FROM: RICHARD B. DYSON -- NHTSA ASSISTANT CHIEF COUNSEL

TO: W. G. MILBY -- PROJECT ENGINEER BLUE BIRD BODY COMPANY

TITLE: 40-30

TEXT: Dear Mr. Milby:

This is in reply to your letter of April 19 to Mr. Schneider asking for interpretations of the motor vehicle controls safety standard, Standard No. 101.

You have asked that we reconsider our earlier opinion that your heater gate valve is a "heating and air conditioning system control" for purposes of Standard No. 101. We see no reason to modify our earlier view. A control, as you have described it, that allows hot engine water to flow through the heater cores is clearly a heating system control, requiring identification as such. Table I of Standard No. 101 allows you the option of choosing your own form of identification. Perhaps a legend such as "Water Control" and a designation of "Winter" and "Summer" positions would clarify your intent that the valve not be used as a temperature control device. However, pursuant to paragraph S4.3 this control need not be illuminated, if, as appears likely, it does not direct air directly upon the windshield.

You have also asked if the cable-operated fresh air door whose function is to control the air that passes through the heater cores is also a "heating and air conditioning control." It appears that this control serves a function similar to that of the heater valve, and that identification is also required, with words or abbreviation at the manufacturer's option.

Finally, you ask if the defroster identification may be preceded by "RH" and "LH" to identify the right hand and left hand defroster systems respectively. The answer is yes; we have no objection to this form of identification.

Yours truly,