Corvette Factory Alarm Relay

[Geoff C.]

[Joe L.]

Re: Corvette Factory Alarm Relay

Geoffrey and Rick-----

When GM discontinued the 68-E77 "anti-theft" horn relay, GM #1115878, they specified no replacement for it. Usually, that means that there is no available part in the GM parts system which will replace it. But, not always.

L77-80 used a diferent "anti-theft" horn relay. This piece is GM #356284 and it's still available for a GM list of about 35 bucks. The original GM #1115878 was a 3 terminal relay and the 356284 is a 4 terminal relay. I just have a feeling that the 356284 relay could be made to work for earlier models. Study of the electrical circuits for the early and late 1977 "anti-theft" alarm systems might reveal the differences and give a clue regarding "adaptation" methodology.

[Tony H.]

Re: Corvette Factory Alarm Relay

Joe,

Can you say if the GM-discontinued,68-E77 "anti-theft" horn relay, GM #1115878, might have been used in other GM vehicles that might be found at a junk yard?

If so, Rick, you might be able to find one that way.... Just a thought.

Tony

[Geoff C.]

Re: Corvette Factory Alarm Relay

Sir,

I already checked GM car line usage for this 68-E77 relay. The Chevrolet Dealers Parts & Accessories Price Schedule circa October 1, 1982 lists no other car line (Buick, Olds, Pontiac, Caddy, GMC truck) as using this relay. If the book is to be believed, then only the Chevrolet brand used this part. If they put factory theft alarms in mainstream Chevrolet models in the 1970's perhaps it is a metal car junk yard candidate? Or was it only Corvette? Why would anyone steal a 1976 Nova or 1968 Biscayne?

Geoffrey Coenen

[Chuck G.]

Re: Corvette Factory Alarm Relay

Agree with Doc on this. The alarm relay has become one of the "holy grails" of Corvette parts. No replacements are available to the best of my knowledge. What to do? I can offer 2 suggestions. First, call the Corvette dismantlers, junk yards, and used parts vendors to see if you can find a used one. The second is to search the flea markets....Corvette Carlisle and Bloomington Gold are 2 "exclusive" Corvette meets that come to mind. FYI...the 878 relay looks like a midyear horn relay...cad/zinc plated cover....stamped "878" on the underside or flange....3 "prongs" as Joe said. Chuck

[Mike McKown]

Re: Corvette Factory Alarm Relay

If somebody will tell me where to look on the car, I'll see if I have one for the man. I scrapped out a '76. Saved most of that kind of stuff.

[Clem Z.]

why can't you

just take the guts out of the orignal and install any 12 volt relay inside the case???

[John H.]

Re: Corvette Factory Alarm Relay

It's a very simple device - looks just like a regular horn relay, except it doesn't have the busbar with the two screws. Has three spade connectors - #1 is 12 volts in for the relay coil, #2 is ground for the relay coil, and when it's energized, #3 is connected to #1. I used to use them back in the late 60's in pairs to make a "latching relay" circuit for home-brewed car alarm systems.

[Mike McKown]

10-4 *NM*

[Lee McGlamery]

Re: Corvette Factory Alarm Relay

Hi Geoffry - I just had my inoperative anti-theft alarm restored for a very fair price. It looks and works like new. Please advise me at leemcgla@bellsouth.net if you need any additional info.

Thanks

Lee