a/c redo 6.2l 1993 RV

[stone]

Did the tps set and made another 1000 mi. and had a good feel the fuel cleaner and the adj. did change the power and the shift pts and the down shift,got 12.7mpg so not bad for a class A. Well now I need to get the a/c working and it has been open a while, the compressor is bad the hoses are gone, at least the openings were covered so I hope when I put the compressor on, the hoses and new dryer canistor and orifice and evac several times I get lucky.Any suggestions on compressor sources and which will interchange.I would like to get a lot out of this since the RV is large and gets real hot inside.I am also worried about added heat to the engine and if putting electric fans might be worth it,this is not an add on, it came with the a/c on it.As far as the heat I also found the added thermocouple to read exhaust temp but the cable has been cut and the gauge isn't working,I need to find a replacement cable or a way to splice it properly and make it work as it should.One other area that is not letting my A/c work is the vac pump,it is a belt drive hard to get to one any ideas on the best way to find its problem will be great.Is it possible or available to use a 12 volt electric vac to provide the vac needed to run the modules in the vent heat and a/c system as well as the cruise control when I get around to redoing that?

[convert2diesel]

Pretty hard to beat the Harrison R4 AC compressors that were commonly used on these rigs. They are plentiful and realitively cheap (compared to the Jap stuff that is used these days). Most auto parts stores should have a listing for one. Shop around. Some AC shops may have some old stock they will sell to you cheap but make sure the unit has been stored with the oil in it. Test the clutch and turn the compressor to make sure it turns freely with no hard spots. Have the same shop charge up the system for you when your done. That way they can't blame you if the thing leaks.

Many European cars (and some older NA cars) had electric vacuum pumps. Check out your local Pick and Pull. Any of the 80s large cars with the tiny engines needed these pumps because the engine spent most of its life with the throttle plate standing on its end, thus no vacuum. Unfortunately, the drag racers love these pumps and they are one of the first things to go after the car is sent to the bone yard. Volkswagen and Mercedes used smaller ones (more then enough for AC vents) for power door locks and such.

From 1990 to date, GM used a non-vacuum cruise control module on their cars. It gets its signals from all the same places as the vacuum ones and they are much more precise, and reliable then the vac units. A little wiring diagram homework and you should be able to wire one in. They even share the same plug. All of the last generation of full frame GM cars (Caprice, Buick Roadmaster, Cadillac Fleetwoods-RWD and the Olds Custom Cruiser) used these modules and with the number of these cars sucked up in the C4C fiasco, there are a bunch of them in the bone yards. These units work far better then the vac versions and if you get one from a full size car or one of the larger FWD cars, then the actuator cable is long enough to give you lots of wiggle room to adapt them to your RV.

From my experience, K type thermocouples are calibrated with the gauge assumng a fixed wire length and wire size (overall resistance). You might have to try to find a known heat value to test your connection. Boiling water is a constant (depending on altitude) but that may be too cool to test your gauge. The red portion of a common candle flame is just shy of 1,500F, assuming your gauge goes that high. Google "flame temperature" and you might find something usable. If you still have the documentation for the gauge, it should have a section on wiring and calibration that will get you in the ball park. Either that or buy a matched gauge and thermocouple.

Hope this helps.

Bill

[stone]

Thanks Bill,sorry for the time I was laid up a while, That is some helpful input and I will be in the bone yards soon,I prefer electric cruise if I can get it and the vac will only be for the a/c heater actuators to select defrost and such so the idea of the vac from those cars will be great to find.On the cruise is the one used on the big units olds and such the actuator and module and any accessory wiring the way to get all I need to adapt it to what was there?I do have the GM factory book on all wiring on this chassis and have some experience in rewire and mod work on large diagram and units.When I find a compressor I so far found one at 128.00 refurb for a 6.2 burp it should be the one but still looking,when that is found I will be getting hose made and a new dryer this unit has been open for years and I have all the equipt. to do the complete pump down and tests supposedly trained to do so but old is old and not as flexible as I once was but should be able to do it fairly good if no other components are bad like the evap or cond. I don't have any paper work on the thermocouple or gage but plan to contact manufacture to see what can be done It seems to me if old BUD had the pump done and intake opened and exhaust I need to watch the temp when pulling hills since it may get hotter than wanted,any knowledge of the temp range best for the 6.2 exhaust the thermocouple is in the down pipe after the y-pipe so both sides are read.Should be taking another 1000 mi run in few weeks if I get some done or, if needed to be at in laws when called due to health issues there, not able to just tear it down as I want.

[convert2diesel]

Stone:

Check these guys:

http://www.auberins.com/index.php?main_page=index&cPath=5&zenid=f53b6d385b0cf2ff964dc6a0c49117da

It may be cheaper (and faster) to just replace everything. Should be able to do your EGT for less then 75 bucks. The nice thing about these are that they need to be calibrated and they include the wire gauge/length calculations in the manual. edit note: just read the online manual and it looks like the meter now does the calibration for you when you first hook it up. It now looks like its plug and play.

Be careful when buying your compressor. If it has been on the shelf for any length of time not only do they tend to sieze up, but the front seal dries out and will leak when you add pressure. If possible, have them pressure test the unit before you take delivery.

If memory serves, the wiring for both the vac powered cruise and the electric version share the same wiring and plug. Just do a quick wiring check before you get into it.

VW bunnies, especially the newer ones, have a neat little vac pump to operate the door locks and such. Should be lots of these little cars in the yard. More then enough to run your HVAC doors (maybe a little bit slower but gets the job done)

Hope this helps

[stone]

Thanks they have good things I did get the egt unit and some cable to replace the patched up one if the couple is bad I can get it too.This unit is not bad and I like the size and it takes less space where I have to put it.Will be looking in the yards for the bigger vac but if none the vw sounds ok I have an accumulator so volume may be okay.Plan to look for 90's gm caddy or so for cruise unit the best I can hope is it will be one I may can get some documents about so any changes i need to do will be noted,some older repair manuals covered them.

[convert2diesel]

Careful with the Caddys. Many of them had traction control which ment that the throttle, cruise and the pedal all go into a barrel affair. The cruise cable is quite short on these. Better to find a Buick Roadmaster or Chevy Caprice 91-96 w/o traction control.

Bill