86 with 3800sc seems to be running fine after being on and off the back burner for a long while. One of the last things to do is to get the AC up and running. Reading on here, I have the basic understanding of what needs to be done but looking at a local junkyard, the AC hoses seem to vary quite a bit. I had Ryan program the ECM with the AC switch and I need to get a 3800 hose with this switch on it. Some at the yards have them on it and I'm guessing that the others have it farther away from the compressor so I didn't see it.
Question is, and anything I haven't thought of, What make and model car would be the best to get the hose from that has this switch inline near the compressor? Also I'm sure I will also need another compressor but guess I could try this one first. If so, which compressor? Do they all hook up the same because I was thinking that they did appear to be different in the junk yards.
Don't know if it is any help but here's a couple of pics
Edit to add: 86se with stock '98 3800sc and 98GTP programming
It's in the 90's now and AC would be nice
Thank you for any help,
Steve
[This message has been edited by JumpStart (edited 06-26-2014).]
I'm going to take mine to a AC Hose shop. the little muffler has to go, and a schrader valve must be installed inline for the 3 wire switch going to the ecm
I have noticed some with and without the valve on the piece near the compressor. I was wondering if anyone knew which year car used this type and are all the 3800 compressors alike?
Can't say if all 3800 comp are alike, I used a Fiero 4 cyl compressor., but the valve is used 1998 up" wired" 3800SC (I Take it your Harness is wired per GMTUNERS specs) . Needs to be there to power up and cycle the compressor by the computer.
IF you don't want the compressor to "cycle" (be run by the computer), you can leave out the valve and just run a hot wire by way of a switch to the compressor.
We made up the attachment hose using a Grand Prix Compressor and hose end . The Fiero hose end is at the other side. We aluminum brazed a nipple on the high side line for the A/C pressure switch that inputs to the PCM. You need the high side switch to prevent excessive pressure that can damage the system. After evacuating and charging the system, the A/C gets so cold it will freeze you out of there.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 06-27-2014).]
It's not a switch it is a pressure sensor (transducer). The ECM won't turn on the compressor if the pressure gets too high, but it will also not turn it on if the pressure is too low.
Full sized cars with the 3800 will have the pressure transducer located already on the lines at the back of the compressor. Buick Park Ave, Buick LaSabre, Pontiac Bonneville.
+1 on don't hotwire the compressor on.
I like putting the transducer at the back of the compressor to keep the wiring more compact. There is already a wire for the starter, the #1 knock sensor and the A/C clutch. Running a single sensor wire to the firewall seems "messy" to me.
Dennis, What year Grand Prix" Hose end" is that ? The ones I've seen the hose bends around" towards the front of the compressor". ( all the front wheel drive 3800 compressor lines I looked at were like that) Haven't seen one like what you pictured. thanks
Dennis, What year Grand Prix" Hose end" is that ? The ones I've seen the hose bends around" towards the front of the compressor". ( all the front wheel drive 3800 compressor lines I looked at were like that) Haven't seen one like what you pictured. thanks
That end was taken off a 2006 Grand Prix A/C hose. The earlier hoses may have been different.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Full sized cars with the 3800 will have the pressure transducer located already on the lines at the back of the compressor. Buick Park Ave, Buick LaSabre, Pontiac Bonneville.
What about the little tank thing? Its also near the compressor on the Fiero. Are you saying that the full sized Buicks/Pontiacs have this and the transducer next to the 3800 compressor? I thought I had seen some that the tank thing would be in the way on the Fiero.
Ok, I read that the a/c bracket will bolt up after drilling out the mount holes and the 84-87 compressor will work by switching the pulley. The 88 has the right pulley for the 3800 belt. I have both an 88 and 87 compressor and brackets I can use if I go this way for being easier but my ECM is programmed for the 3800 pressure sensor. Is there any certain way of doing this considering the ECM and sensor?
so I would still need to get the 3800 pressure switch braised onto the Fiero a/c line? If it is needed, why is there not one already on it? ( assuming it has to do with the ECM already programed for it)?
Maybe what I am asking is do I have to have the pressure switch since the ECM is programed for it or can I just cap those wires off (the 3 for the sensor) and run just the 2.5 compressor as is? Can I run the new freon this way?
Steve
[This message has been edited by JumpStart (edited 07-06-2014).]
ok, I wasn't thinking on that last post lol. The A/C will not even turn on without the signal from the 3800 sensor. Any tips on the best way to get a sensor on the hose I already have, there is an A/C shop near by, or would there be any advantage to using the 3800 compressor over the 2.5?