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Hello there. I’m getting ready to tackle replacing the driver’s side window motor on my 91 Grand Prix SE coupe. I was curious if anyone had any experience dealing with these. It looks like I need to grind/drill out rivets, remove the seals around the window frame, and the whole assembly lifts out; window, window regulator, and motor. The window looks like it’s riveted to the regulator so the window has to come out also. Does that sound right?

^ Jeez Chris, you've got some arrangement I've not come across, even our previous '90 GP fitted with the V5 had no electrical fittings on the tail end of the compressor housing. Obviously the engine wiring harness goes to the switches? Another thought came to me, our friend in the Russian Federation has done a heart transplant to his GP, the powertrain is a Cadillac 4.9 out of a Brougham/Deville/Fleetwood, all which didn't make use of the V5.

my 1990 for sure has a pair of electric switches on the back of the compressor

Negative......... all of the early design housing of the V5 will have a pair of *mechanical* internal switches inserted into the back housing, they are held in place by a pair of inside C-clips, they work in conjunction with the swash plate to regulate the pressure differentials between the discharge side pressure & the suction side pressure. They have nothing to do with *electrical* switches and are completely self contained. Later models of the V5 (circa 1999) have a completely redesign back housing which has done away with those 2 *mechanical switches*, improvements in the compressor internal design eliminated them altogether.

That is correct, my 1990 has the same setup.

No! on 1989 model year - low and high pressure switches mount on compressor, fan pressure switch near the dryer

Normal system voltage output should be approx 14.2v, one can check that with a simple voltmeter. that voltage level is seen on the voltage gauge in the cluster, if one loads up the system at engine idle note with the meter what the system is dropping off to. I've been where you are, to get around this 2 years ago I replaced the original output 105 amp alternator with a 140 amp unit. Idle voltage issue was significantly reduced.

The v5 has only one single high pressure blow off valve mounted into the back end of the housing. The system low pressure switch is as you noted next to the receiver/dryer.

about 12v and below

low and high pressure switches mount on compressor, fan pressure switch near the dryer

How much is it dropping? These cars had a rather undersized charging system from factory. Especially a TGP with the terrible braking system.

The pressure switch is a necessary device to prevent the compressor engaging when there is not enough refrigerant in the system.

Yep, that's what happens at idle, the idle speed needs to be at least 800rpm to combat the load on the charging system. In those situations put the trans in neutral, raise the engine rpm to get the charge rate back up. Something one can do is to pull out the secondary fan relay to prevent the secondary fan engaging. The secondary fan only engages when the a/c is on, it very seldom engages for engine temp cooling purposes as it doesn't engage until the engine temp is near 220F degrees. The side effect of this is the condenser will not dissipate as much hot air as both fans running.

Was this the mode from the factory? then what is the purpose of the pressure switch near the dryer?

But it turns out that if the car is stuck in a traffic jam at idle speed and the brakes are pressed, and plus two fan, the voltage drops alternator - new 105a

Super stoked for this one! Just picked up this 93 tonight. One owner Michigan car! Not a spec of rust accept for around the windshield trim! Undercarriage looks virtually new! Has been sitting since 19, so some gremlins to work through! New top, but not a documented time of replacement. Has the usual oil leaks etc, and a horn / headlamp issue. But I am looking forward to getting acquainted with it! I think it’ll be a good pairing for my 95 as well.

what if i js took out the rear monoleaf and put some spacers would it work ? i mean the ride will obviously be bad but as long as it will actually drive like that i think i’d be fine with that

Not really any of those as I recall. once upon a time someone made lowering leafs, pretty sure unless you find one of those your only option is DIY coil overs, Its been done here but honestly I was never into that so I can't speak to it

When I first started charging the A/C system, the driver side fan kicked on. It might have kicked on when I actually pressed the climate control panel. As I started filling the system...I think with the start of the 2nd bottle of freon, the compressor kicked on as well as the passenger side fan. Yes, when I'm on the HWY or Interstate, I'm assuming both fans have shut down long ago by that point. I can then hear them, (and feel a little bit), when I'm back in city driving mode.

I should also add that the coolant fans engagement is speed dependent, when the a/c is on the pcm will disengage the fans as the vehicle speed increases to the point when they no longer need to be.

anybody know the cheapest quickest way to completely drop the rear of a cutlass with the mono leaf suspension? ps no judging i recently picked a up a running/driving 92” cutlass supreme for 500 dolla so im trying to make something to scrape the floor

I just rebuilt the A/C system in the International and yes, both fans run when the A/C is on. The fans and the compressor is doing exactly how 55trucker is describing.

Indeed it is........ both the primary & secondary fans will engage. The low pressure sensor engages the entire system when the system is above approx 40lbs, the compressor does NOT cycle, once engaged it runs 100% of the time the a/c is turned on (depending on the volume of system charge).

TGP 1989 When operating without the air conditioner on, everything is fine. But when we turn on the air conditioner, even on a cold engine, both the main and additional fans turn on immediately. The question is - is this a normal operating mode? After all, the pressure sensor should be responsible for turning on the fans, but the control unit ignores any state of the sensor.

This thread seems old. Did anyone ever find replacement top header seals. Looking for a 1992 cutless supreme