87 300D Mystery AC Wiring by PO

[Tpawlik]

I have some pictures of A/C wiring done by the PO. I have A/C and heat. However, the A/C or heat work when the Economy, A/C or Defroster button pushed. I think all the air comes out of the dash vents. It takes about 15 minutes for the A/C or the heat to start working once the button is puhed on the CCU. Can anyone tell what the PO was trying to accomplish by rewiring and adding a 30A relay. They tapped the a wire going to the compressor and a switch, then wired in the relay and connected all to a hot terminal near the fuse box

[sixto]

It looks like they bypassed the Klima relay in a rather unelegant way. If wires don't scare you, we can talk you through getting things back the way they should be, or at least closer to the way it left Sindelfingen.

Sixto
87 300D

[Tpawlik]

How is this relay different from the Klima relay and where should it be? I am just finishing restoring a 62 Olds Starfire. I had to buy a relay like the one the PO used for my power window and top circuit because an original relay is no longer available. It sounds like this wiring is not affecting the inproper operation of the CCU. I would like to put things back to original and get the A/C and heat working properly, even if I have to buy a new/rebuilt CCU.
Thanks.

[sixto]

I've always wanted a Jetfire just because it's an early factory turbo application. Does the Starfire have a new fangled engine like a 215 or odd fire V6? Does it have the tranny in the rear like the early Tempest?

I suspect the Klima or low pressure switch acted up and they bypassed it completely rather than more subtley (is that a word?) with a similar relay at the Klima socket.

Step 1 is to determine if there's a PBU ground signal at the low pressure switch behind the left headlight. There'll be a couple of switches attached to the drier. One will have a couple of spade connectors, the other will have a couple of pigtails. We're after the one without pigtails. One wire comes from the PBU, the other goes to the Klima socket behind the battery. Find the PBU wire and test for ground when the compressor should engage.

Sixto
87 300D

[sixto]

The Klima relay is in the cubby behind the battery. Remove the plastic shield and you'll find the ABS controller, OVP relay and a bunch of electronics. The Klima relay is roughly 1" by 3" on top and 2" tall and has 12 positions but only 11 actual pins.

Besides converting the PBU ground signal to +12V for the compressor, it also serves protection functions like cutting the compressor over ~125*C coolant temp, compressor rpm less than 30% of engine rpm (compressor drag) and disengaging the compressor at WOT below ~2000 rpm to aid acceleration. The so called ice cube relay bypass does away with the protection features which can cause the compressor to disegage inexplicably.

Sixto
87 300D

[Tpawlik]

I'm pretty sure they attached a wire to the switch with spade terminals and to the new relay. The car is not running at this time, waiting on a new lower radiator hose and t-stat. I will check on the ground you mentioned and let you know. Does this wiring have anything to do with the CCU not funtioning properly?

[sixto]

Good question but probably not. How, exactly, is it not functioning properly? If you mean the delay in getting air to the expected vents, I'd day you have long day's work ahead diagnosing the vacuum distribution system and vent actuators. If it takes 15 minutes for the blower to kick in, that's a different problem that can take the better part of a day as well

Sixto
87 300D

[Tpawlik]

On the Jetfire, they are really hard to find in running condition with the original turbo. Reliability problems forced most people to abandon the turbo and install a 4 bbl carb. My car has a carbureted 394 c.i. engine.
Vacuum system-I found a tear in a rubber elbow on the gizmo mounted on the strut tower that the alda line goes to and 2" section of vacuum line missing on a rubber Y that runs on top of the fuel filter. Sorry, I haven't received my shop manual yet so I cannot accurately identify the components these vacuum lines go to. I noticed when driving the car last that it took more effort than normal to take the car off of cruise control with the brake pedal and the engine was not making full power. I found some plastic tubing at WWW Grainger that looks like a good substitute for the miles of vacuum lines running thru the engine compartment. I think I shuld change them all and the rubber connections. Maybe vacuum leaks are the suorce of other problems I am experiencing.
Thanks for your advice.

[sixto]

This should help -



a is a vent line that hangs loose in the driver footwell area
b is a line from the key switch for the engine shutoff actuator
d goes to the modulator on the driver side of the transmission

Not shown is a line that tees off the big plastic line to the brake booster and continues to the cabin to the key switch.

6 is the engine shutoff actuator
103 is the ALDA
Y30 is the overboost protection switchover valve
Y29 is the cold shift softener switchover valve. That's my name for it, anyway.
123 is the transmission vacuum amplifier, also known as the blue flying saucer or BFS

If you promise to drive only off road and only on diagnostic trips, you can ignore/cap/plug the vacuum lines that go towards the right headlight (not shown in this diagram). Those lines serve the EGR and ARV emission control devices.

Sixto
87 300D

[Tpawlik]

Thanks. It helps when I actually know what these devices are supposed to do.
Back to the A/C. The fan turns on with the vent/fresh air/A/C button immediately. It's the compressor that starts when it wants to.

[sixto]

There are two pressure switches on the drier behind the left headlight. One is a high/low pressure cutoff switch with two spade connectors, the other is a high pressure aux fan trigger switch with two pigtails. Dig behind the battery for the Klima relay and remove it from its socket. It only goes in one way and I'm pretty sure there's an index pin so you can't get it wrong. With the Klima relay out of its socket, test each of the wires to the high/low pressure cutoff switch, let's just call it low pressure switch from this point, for continuity to ground when the PBU should be sending a signal to the compressor (DEF at any temp or up and down arrows at MIN temp, EC and off mean no compressor). If you get an immediate ground signal to trigger the compressor, the problem is in the added wiring. If you get a delayed ground signal, the problem is in the PBU or its sensors. The PBU sensors include the cabin temp sensor by the sunroof switch and the evaporator core temp sensor. I don't remember one ACC system from another. Maybe there's also an ambient air temp sensor, separate from the one with an LCD display in the dash. Any of those could be fooling the PBU into thinking the cabin cooler than it is. Or the PBU could just be goofy.

Sixto
87 300D

[panZZer]

Originally Posted by sixto

I've always wanted a Jetfire just because it's an early factory turbo application. Does the Starfire have a new fangled engine like a 215 or odd fire V6? Does it have the tranny in the rear like the early Tempest?

I suspect the Klima or low pressure switch acted up and they bypassed it completely rather than more subtley (is that a word?) with a similar relay at the Klima socket.

Step 1 is to determine if there's a PBU ground signal at the low pressure switch behind the left headlight. There'll be a couple of switches attached to the drier. One will have a couple of spade connectors, the other will have a couple of pigtails. We're after the one without pigtails. One wire comes from the PBU, the other goes to the Klima socket behind the battery. Find the PBU wire and test for ground when the compressor should engage.

Sixto
87 300D

I know where there is a 200 horse 63 buick special with a 4 bbl in one of my favorite j-yards--a few cars away is the stick bell in another. They dont really do that good on gas or I would have.........

[sixto]

Since I can't afford it, I'll dream about this one -

http://www.hemmings.com/classifieds/carsforsale/oldsmobile/jetfire/1096391.html

Hemmings has a couple other Jetfires but from the brief descriptions they aspire to be parts cars.

I don't know why Olds bothered with a turbo option if they could get a 394 in there!

Sixto
87 300D

[johnscars]

Sixto, the diagram above shows the 62 X vac tube connector in the front, but not connected to tubes. My 87 300TD has disconnected/capped vac tubes from the devices between the air cleaner and the passenger headlight that run ovr the radiator. I was told they were unnecessary to reconnect. Would this contribute to the hard shift from 1-2 gear after cold start up? It shifts smoother after it warms up, and all other shifts up and down are smooth.

Also interested in replacing my water pump. Can't find a DIY, is there a written procedure somewhere?

Tpawlik, I have a spare temp sensor from an overhead light module if you need it. Take care removing the fixture as some are pretty brittle.

John

[sixto]

Confirmed - the two vacuum hoses going the the passenger side area have no bearing on transmission shifting.

Switchover valve Y29 takes an electrical signal from the 50*C coolant temp switch by the thermostat (the thermostat is by the lower radiator hose fitting aft of the water pump, not in the turret by the upper radiator hose fitting). I don't remember if the 50*C switch is opens or closes above 50*C. Regardless, the switch controls Y29 which directs more vacuum and less boost to the transmission amplifier to soften shifts until coolant gets to 50*C. That sounds exactly like the situation you have. Check that the 50*C goes from continuous to ground to open from cold to hot, or the other way, and check for constant +12V to Y29 and a corresponding signal from the switch. Check that the vacuum lines and fittings are intact.

John, water pump replacement is straightforward as water pumps go. You'll need a special tool to hold the pulley while loosening the fan. Here's what Dave M/gsxr uses -



This tool works well to hold the pulley - http://www.harborfreight.com/pulley-spinning-tool-66385.html

I'm assuming you have an 87 300D. An SDL is similar. You can replace the water pump without removing the radiator but there's no time savings, so remove the radiator first:

- Drain the coolant through the petcock in the lower passenger side corner of the radiator, or pull the lower hose if you're discarding the coolant.
- Disconnect the engine radiator hoses
- Remove the two clips holding the shroud to the radiator and set the shroud on the fan. Or maybe you're lucky and have a two piece shroud that can be removed without removing the fan. If you don't have such a shroud, it's only about $70 from the dealer or Phil. Only for the W124, though.
- Disconnect the transmission cooling lines from the passenger side tank of the radiator. Use a wrench to hold the radiator fitting as you loosen the lines so you don't twist the fittings off the radiator. Have a length of hose handy to bridge the transmission lines so you don't lose fluid.
- Remove the two clips holding the radiator to the upper radiator support
- Lift the radiator out of the engine bay

There'a an allen head bolt that takes an 8mm key holding the fan to the pulley. Use the pulley tool to hold the fan as you loosen the fan bolt.

Replacing the water pump from there is straightforward.

This is a good time to check the condition of the belt tensioner. Make sure the tensioner rotates smoothly about the center bolt - no clicking! Make sure it doesn't wobble about the center bolt axis. Make sure the tensioner pulley spins smoothly and quietly and doesn't wobble about its bolt axis. Make sure that the belt damper Heim ends aren't loose or worn which can cause an engine knocking sound.

Sixto
87 300D