Hermit Urban Posted August 21 Share Posted August 21 Last spring a very good auto air shop, where I had taken Harvey for a Freon injection, told me the actuator behind the coolant valve in the generator bay had failed. He said he couldn't find a replacement and had installed manual valve. He had it blowing cold but said I'd have to open/close the valve manually. And then, due to some tinkering I did that I don't remember, I lost all function of fresh air, heat, and AC in the dashboard. Further tinkering produced motion in the actuator two or three times then that was gone, too. The only part of the system functional is the vacuum pump, which now runs constantly when the ignition is turned on. After an epic struggle that would interest Homer I got a direct actuator replacement and today installed it. No change. Flat donkey dead. Tomorrow I'm going to try to find a blown fuse somewhere but my life history suggests it ain't gonna be nearly that simple. Anybody with any wisdom gained from similar experiences? Link to comment Share on other sites More sharing options...
Benjamin Posted August 21 Share Posted August 21 No fan running at all? That would be one place I'd start. The other would be the vacuum. The pump is running so that's the easy part, then find out what you have to do to get it to stop running. It should be connected to a reservoir and pressure switch. Somebody will know if the pressure switch is on the pump or where it is. Basically the pump has to be either not pumping, or the system is leaking. By plugging various hoses with your finger, you should be able to tell if the pump is sucking, and if you can isolate certain hoses to get it to shut off by building vacuum, then find the leak so the actuators work but the pump still shuts off eventually. 1 Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 21 Author Share Posted August 21 Benjamin, thank you -- but my 80-yr-old carcass ain't gonna flex enough see hoses under the dash, much less reach them. I'm not concerned about the pump; either it'll function properly when the rest of the system is fixed, or it won't and I'll replace it. My concern is that all of the electrical circuitry for the entire HVAC system, other than the vacuum pump, runs through the actuator switch. The new switch ought to restore broken circuitry but isn't, and my little senior episode with the ATS, recorded in excruciating detail in another thread here, has taught me not to assume anything. Realization: When I set the dials for AC I don't know if the compressor is running because it's at the other end of the coach, and I didn't start the engine anyway., but I'm assuming it won't. Link to comment Share on other sites More sharing options...
Romeo84 Posted August 21 Share Posted August 21 Straight donkey dead 🤣 Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 21 Author Share Posted August 21 My wife won't write "a$!" in a crossword puzzle . . . . 1 Link to comment Share on other sites More sharing options...
96 EVO Posted August 21 Share Posted August 21 40 minutes ago, Hermit Urban said: Realization: When I set the dials for AC I don't know if the compressor is running because it's at the other end of the coach, and I didn't start the engine anyway., but I'm assuming it won't. Well, there's only one way to find out, isn't there! Link to comment Share on other sites More sharing options...
Benjamin Posted August 21 Share Posted August 21 The vacuum pump was one diagnostic step, as I saw it. Typically the air flow will default to defrost without vacuum, so you could work on the rest first, but eventually the vacuum pump will need to be addressed, I figure might as well do that first. Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 21 Author Share Posted August 21 Benjamin, I've been thinking the pump might be running constantly because, for the reason of all the other failures, the flaps it controls are in a mid-swing position. Don't know if that makes any sense, but the pump, now that I identify it, so log-fall easy to replace if and when. In the meantime, until I get some electrical power into the dials, I can unplug one of its wires. 1 hour ago, 96 EVO said: Well, there's only one way to find out, isn't there! It's a process . . . . Link to comment Share on other sites More sharing options...
Tom Cherry Posted August 21 Share Posted August 21 Basically when my MH starts after being in storage for a while....you can hear the pump run and it replenishes the Vacuum Reserve Cannister. Then you rarely hear it. You CAN purchase a Vacuum gauge..... we old time gear heads had one to "Tune" and such. You can "T" it in. There have been many topics here on such. If you use the search, you will find a lot of information. I'd do that and read... Good Luck... Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 21 Author Share Posted August 21 Thankee, Tom. The pump's my least concern, though. Not expensive and easily replaced if need be. Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 21 Author Share Posted August 21 Significant progress. If I haven't told you that I'm that guy who is always attacked by the weirdest, most unlikely, unheard of, bizarre misfortune, I'm telling you now. I located a 20-amp fuse, specifically 4-14, in the Ignition #1 group of fuses in the electronics bay, with only one tine in its socket. Pulled it out and installed it properly and wallah! Power to the dashboard controls. The actuator is working. Controls switch air flow from floor to defrost but not to the ball vents in the dashboard, and the compressor isn't running and the radiator fan isn't working. But I think the mysterious [reference the male gender phraseology above] is cured and the AC guy who mis-installed the fuse can sort out the rest. He's actually very good. Must have been a bad day. 1 Link to comment Share on other sites More sharing options...
Hermit Urban Posted August 22 Author Share Posted August 22 (edited) Moderator Edit. This was a new topic which is a followup to a current one on the same subject. Merged with original topic. End of Edit. In the event that anyone else's "HVAC bend door actuator" fails -- the device the opens and closes the valve on the coolant line going up to the dashboard radiator and through which all the electrical circuits for the HVAC system pass, vacuum pump accepted, the one with four connection pins in a row (older years) -- they can be found on eBay under HVAC blend door actuator for 199902007 Chevrolet Endeavor, Buick Rendezvous https://www.ebay.com/itm/196555893798?_nkw=HVAC+mixing+valve+actuator+REndezvous&itmmeta=01J5WXYARGA3SNXWTVV7PRPQGX&hash=item2dc3a4ec26:g:ptgAAOSw3PVmvA85&itmprp=enc%3AAQAJAAAA4HoV3kP08IDx%2BKZ9MfhVJKlXZM7vL1OoCVwzBzliXMyUp%2FQJKUkCFi3smr9qoIwEf7FzX26BJfzFoDLuAoCBL6QzbgNXbNaltqNDcU2xOGzKY6SjWTn1aagzKRACRFUlWzXc02TFrMxNE0R5d8r%2F9HNn71JFnG1xmF2fUTaEQWCk%2BYu8owOjqjGjUlWA6I8n%2BOpFLLmDHDJgS6yxCXByA5Tu5GJRoRK8eoauPzwio6SRW%2B4Db36JJYOUu%2BFTb8rdv3EwimBDz%2F7vG3vnADC7EyqnjnI5EHfjAVk7IyaL%2BNp%2B|tkp%3ABk9SR6qs-Z2vZA You cannot get these from REV RV. I got the last one they had back in April and the pin configuration was a rectangle. They were unable to get a response from their supplier about a wiring pigtail to mate with the actuator despite months of periodic phone calls. The supplier, REV told me, ignored them. (And they almost $90 for the actuator they did have while the one I bought online, currently working in Harvey, was only $20.67). Edited August 22 by Tom Cherry Merged with original topic 1 Link to comment Share on other sites More sharing options...
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