Interpretation ID: nht75-3.5

DATE: 07/07/75

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: Department of California Highway Patrol

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of May 21, 1975, requesting answers to two questions "relating to the requirements for 16 or 18 gage wire specified by [SAE Standard] J589" ["Turn Signal Switches"] in Motor Vehicle Safety Standard No. 108.

You first asked:

"1. Once the switch has met test requirements using the 16 or 18 gage wire, can a switch manufacturer change the wire gage to a smaller or larger size for installation and use on a vehicle?"

We are uncertain as to what you mean. If you intended to refer to the vehicle manufacturer, the answer to the question is yes. He may use a gage other than 16 or 18 when the switch is installed in his vehicle. The test set forth in J589 is a laboratory test measuring voltage drop that must be met by a switch when 16 or 18 gage wire is used.

You next asked:

"2. Would a switch which was tested with other than 16 or 18 gage wire (larger or smaller) meet the certification requirements of Part 567 of the federal standards?"

When a manufacturer certifies conformance to Standard No. 108, he is indicating that the turn signal switch will meet the requirements of SAE J589 if tested with 16 or 18 gage wire. He may use any method he chooses to ensure this. This agency does not, through its certification requirements or otherwise, instruct manufacturers how to test their products.

Thank you for your suggestion that we amend Standard No. 108 to incorporate SAE J589 which does not specify the gage of wire for test purposes. We have already proposed adoption of J589b in Notice 3 of Docket No. 69-19.

Yours truly,

ATTACH.

May 21, 1975

File No.: 61.A1588.A3107

James C. Schultz -- Office of Chief Counsel, National Highway Traffic Safety Administration

Dear Mr. Schultz:

Federal Motor Vehicle Safety Standard No. 108 specifies that signal switches meet the requirements of SAE J589. The durability test for switches in J589 states among other things that the voltage drop from the input terminal of the switch to each lamp terminal (including 3 inches of No. 16 or 18 gage wire from each side of the switch) should be measured at the beginning and at intervals of not more than 25,000 cycles during and upon completion of the test.

We would like answers to the following questions relating to the requirements for 16 or 18 gage wire specified by J589.

1. Once the switch has met test requirements using the 16 or 18 gage wire, can a switch manufacturer change the wire gage to a smaller or larger size for installation and use on a vehicle?

2. Would a switch which was tested with other than 16 or 18 gage wire (larger or smaller) meet the certification requirements of Part 567 of the federal standards?

We also note that the current version of J589 is J589b. This version does not specify the gage of wire for test purposes. If the answer to question one above is yes, we strongly recommend that consideration be given to amending Federal Standard No. 108 to indicate that switches meet the requirements of SAE J589b instead of J589.

Very truly yours,

WARREN M. HEATH -- Commander Engineering Section, DEPT. OF CALIFORNIA HIGHWAY PATROL