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I have a clicking behind the glovebox/pockets on the right side of the dash! It sounds like a relay, and it drains my battery, ON all the time and have to disconnect my Batt.!
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Re: C3 whats behind the?
Larry----
You didn't mention what year C3 that you're talking about; there are differences with respect to interior electronics over the years. However, during the 68-72 period there were no relays or similar devices located behind the right side dash panel. All there was were the radio "convector" (which is solid state and makes no noise) and the signal flasher located in the lower right corner (which IS a electro-mechanical device and may make some noise).
The closest relay device to the area that you mention is the windshield wiper motor relay which is located under the forward portion of the forward console.In Appreciation of John Hinckley -
Re: C3 whats behind the? *TL*
Larry,
Any chance you have a 1971, 454 with AC?
That is the only car in 1968-1972 I can think of that has relays in that area. The use for those relays is a long story, so please confirm your year and options so we can help you.
Terry
TerryComment
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1971, 454 w/AC What's behind the P/S dash pad? *TL*
Larry,
Now that I read your post further down confirming a 1971 454, I will guess you have AC. Those relays behind the passenger dash pad are designed (when properly working) to turn on the AC compressor clutch on engine shut down to provide some mechanical drag to help stop the engine and prevent "run-on."
So long as you don't intend to have the car judged for a performance verification (PV), just remove the passenger side dash pad. Working from memory - two screws in the door jamb, two in the left side of the pad (accessible from the driver's seat - keep track of which screw goes in the upper hole and which in the lower. They are different lengths and if you get them mixed up you can easily poke a hole in the dash pad), and three interior color screws across the top of the dash pad. Simply unplug the relays and your battery problem should be cured. The down side is your engine may be hard to stop now and you may have to turn it off and let the clutch out to stop it. On the other hand it sounds like the system may not have been working properly anyway, so you may notice no difference in operation except that the battery will now not discharge prematurely.
On the chance that a PV is on your to-do list, you might want to start looking into the operation of that system. A little diagnosis with the 1971 Chassis Service Manual (CSM) may help you determine which relay is bad. Since those relays are made of unobtainium, and are in the same category as chicken lips (:D), you may want to start looking for them sooner rather than later.
Terry
TerryComment
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Re: 1971, 454 w/AC What's behind the P/S dash pad?
Terry-----
Now that's an interesting piece of information that I was not aware of. I'm going to have to "bone up" on this system.In Appreciation of John HinckleyComment
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Re: 1971, 454 w/AC What's behind the P/S dash pad? *TL*
Joe,
My experience with this system is - if you don't have to go there - don't.
It is one year only and only 454 with AC, and I think manual trans only as well, but I would have to do some checking to see if it was transmission limited. It was not unique to Corvette - I think all 1971s with that drive train got it, but it is unique enough that the parts have been long discontinued.
I just looked in the 1968-1972 Operations Manual & PV Test Guide and I see I did not limit it by either transmission or engine type. My memory is causing me to think that may be an oversight - I will have to check more into this to see if indeed it is limited by engine size and transmission, however, I am absolutely sure large motor with AC and manual transmission had it..
I learned about it in order to do performance verifications and to write that manual for 1970-1972. I rate the odds of finding a working system real low now that more than thirty years has passed.
A working system will apply the air compressor clutch for three seconds on engine shut down and also block the heater/AC blower motor for the same length of time. There are two relays mounted to the heater box, behind the passenger side dash pad. One is the blower blocking relay and I believe the other is an apply relay.
Terry
TerryComment
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Re: 1971, 454 w/AC What's behind the P/S dash pad?
I may be incorrect but I believe that all '71's had this system. The "anti dieseling relay", part # 3996203 energizes the compressor on shut down. If it fails the compressor may not energize at all! The blocking relay, part # 3996204, is the other half of the duo.Comment
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Re: C3 whats behind the?
Yes the car is a 454 with factory air! Thanks Terry and the rest of you guys!Comment
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Correct!!!
The relays, by P/N called out were used on all '71 cars with A/C. I'm surprised Terry forgot sitting in my 'Lil Red at Joplin doing a Founder's Ops check when I 'demonstrated' that feature of the car. Terry thought that was keen new knowledge and brought other members of his National Team over to see/hear the system work. Roy Sinor 'beat' both of us for running the car's engine excessively on the indoor judging field!!!Comment
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Memory - it's a terrible thing to lose! *TL*
Don't be surprised Jack. All those bent chromosomes of my youth are coming back to haunt me.
TerryComment
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Re: Memory - it's a terrible thing to lose!
Terry-----
MEMORY can sometimes be a terrible thing to POSSESS!In Appreciation of John HinckleyComment
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Re: Memory - it's a terrible thing to lose!
Joe —
That's why I write down the good things and forget the bad ones. For example, in the attached web-page, I've nearly suppressed the memories of the bad events of this escapade.
The Blue FlameComment
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Good chuckle-Terry/Joe!!! *NM*
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