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A/C time delay relay?

Richard Cranium

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According to my service manual, it looks like I'm missing this.....

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What's this relay do & has anyone got one to sell, or have any ideas about a substitute?
 
If it is on AC circuit it will be to stop it from shutting off and restarting immediately as it will be hard on clutch starting against full head pressure
 
RC that's time delay relay for ign.key lamp on my '68. Stays on for 10-15secs after opening door. Added that option to mine yrs ago.
 
RC that's time delay relay for ign.key lamp on my '68. Stays on for 10-15secs after opening door. Added that option to mine yrs ago.



Actually, it's not as it's wired into the a/c circuit, but I wonder if it's the same delay relay?
 
Bm02 has to be right. My relay is a 3-prong. I see yours feeds off blower sw, I agree again with bm02; it's probably to stop fuse from blowing when switched on too soon with high head press. in compressor.
 
My '68 was w/o a/c you have to be kidding? How many a/c's were sold in '68? lol of any model. Just saying. I don't think it'd be that big a deal, usually a/c is either on or off on a car. Not quite like an rec.vehicle.
 
If your a/c fuse is 20/25 go to a 30a. You have enuf brain matter to not switch on&off willy nilly.Only need about (?) 4-5 min. for the pressure to kinda equalize.
 
It is not the fuse it is the clutch on front of the compressor that has to lock in
So it would be like you starting on a hill in high gear
 
My aftermarket Classic Auto Air has no such feature and does not communicate. It cycles when it feels like it. This has never been a problem. Also, there is no idle input to increase revs. The Big Block does not mind. It often seems like it cycles too frequently, but has worked perfectly for about nine years. Never a clutch, never a recharge. R134.
 
Richard, are you sure yours is missing? It is located on the very bottom on the right hand side of the heater box. If yours is missing, you have a hole there. The two wires (brown and blue) hook up to it on the very bottom. Here are a couple pics. If yours is missing, I have a spare heater box that has one.

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Hot ****, that's where they go?!?!?!?! I figured that it was some sort of relay like a flasher relay.

You da man!!!! :thumbsup:
 
Richard, are you sure yours is missing? It is located on the very bottom on the right hand side of the heater box. If yours is missing, you have a hole there. The two wires (brown and blue) hook up to it on the very bottom. Here are a couple pics. If yours is missing, I have a spare heater box that has one.

View attachment 408079 View attachment 408080

Question please. How can you determine if the time delay unit is working? I have a 68' Coronet 440. Does it make any sound(s)? Is it by function or lack of function that you can determine if the unit is working or not? Or both? Trying to figure out if mine is working. The A/C is not connected but all a/c heater button and vacuum lines, actuators are working. My brown wires (heat) and blue wires ( A/C) are connected. I do know that when HEAT button is pressed, the fresh air door is supposed to open (open to fresh air) yet my fresh air door remains closed to fresh air when the heat button is pressed. All the actuators are connected, vacuum tested and working. So I was guessing that since the time delay is also connected to the rod side of this vacuum actuator, that it's function also has something to do with changing the vacuum and allowing/forcing the fresh air door to into the open position. Anyone tracking with me? Thank you!
 
Question please. How can you determine if the time delay unit is working? I have a 68' Coronet 440. Does it make any sound(s)? Is it by function or lack of function that you can determine if the unit is working or not? Or both? Trying to figure out if mine is working. The A/C is not connected but all a/c heater button and vacuum lines, actuators are working. My brown wires (heat) and blue wires ( A/C) are connected. I do know that when HEAT button is pressed, the fresh air door is supposed to open (open to fresh air) yet my fresh air door remains closed to fresh air when the heat button is pressed. All the actuators are connected, vacuum tested and working. So I was guessing that since the time delay is also connected to the rod side of this vacuum actuator, that it's function also has something to do with changing the vacuum and allowing/forcing the fresh air door to into the open position. Anyone tracking with me? Thank you!

Per the Service Manual

Time delay Relay (CoronetandCharger)

A vacuum actuated time delay relay is located on the bottom of the fresh/recirculating air door housing. The purpose of this relay is to reduce the interior windshield condensation to an acceptable level.

When the ambient temperature is above 25 degrees, and the heat or defrost buttons are pressed, the air conditioner will go on for a period of 1 to 10 minutes.

If the system is shut down for less than ten minutes no delay will occur upon restarting. The relay will reset automatically after ten minutes shut down.

It was not clear to me how this device actually works when I cleaned and restored my AC box.
 
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Keep bothering me if you don't get a reply. I need to pull my kick panel to take better photos but can do that if needed.
 
Looks the same as mine Richard. Red tracered hose. Is yours not working properly?


Not sure if it is or not. I don't know how to tell. The only reference I can find about it in the service manual is what had already been mentioned here. No pictures at all of it and no diagnostics for it.
 
I looked at a spare heater box I have and it shows the red tracer hoses coming off of the rod side of all three actuators. With the bottom actuator being the one you are asking about, that hose coming off of the tee goes to the #3 spot on the 7 hose connector. That is if you are looking at the hose connector with the 4 hoses on top and the 3 hoses on the bottom and number the hoses 1,2,3 & 4 from left to right.
Do you have your AC charged up and working?
 
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