Oldsmobile Bravada

1999 Oldsmobile Bravada Electrical / Lighting Systems   

My remote lock control has stopped working. I replaced the battery, but still does not work. All the locks work fine, just not remotely. What are the most likley causes, the remote it self or some controller in the car?

Hi, When replacing the battery in the key fob it is recommended to hold down both the lock and unlock buttons at the same time for a few seconds to synchronize the transmitter with the receiver. Try that.

I have recently been in an O'Reilly's parts store and saw that they had a test device where when activated it can detect if your remote is sending a signal. Pretty cool, costs nothing to try.

Any help?,

Roger

Yes, that is cool and I will deffinetly try it. Thanks

I hope to hear from you when you get a chance to give me an update.

Roger

1999 Oldsmobile Bravada All Part Groups   

After driving on the highway for about an hour the vehicle begins to jerk when I hit bumps and then when I get into town and slow down the vehicle jerks a lot during acceleration. When only driving around town, not having been on the highway there isn't any kind of jerking action that I can detect.

You might check the gas you are buying, as during the winter months, there is more moisture in the fuel. Also get it scanned for codes. Many auto parts places offer that service for free.
If it runs smooth, I sometimes do a "wiggle test" by trying to replicate the problen by moving the wiring and hoses under the hood, when it is running.Stay away from moving parts when doing this.
If all else fails, try to have a shop hook up the scanner, and take it for a test drive.

1998 Oldsmobile Bravada Heating / Cooling System Malfunction  Always

Suddenly started to blow HOT air as if thermostat was set at max temp. The temperature control has NO effect. The AC compressor works fine as the lines are cold and cycles OK. While the compressor is working, the air from the system is still passing thru the heater core. There must be a control module and where would it be? The dealer wants to replace the compressor for $1600 and I told him NO!

You say the compressor is engaging and the lines are cold(low pressure I take it)but you still don't get cold air in the cabin.My take from this side of the screen would be at the control head.It may be engaging the compressor but not the control vents.If these vents stay in the shut posision due to the control, you're not going to get any air.Let mwe know of your findings and I'll try to help you thru.
Good Luck.
Paul

I do not understand when you say the "control head". It seems to me that since the temp control has NO effect, the AC seems to work, the problem is in whatever controls the flaps that changes the airflow from over the AC coils vs the heater core.
At the moment it is "stuck" in over the heater core position and get only Heat in the cabin.
Is there a "control module" and how do I locate it??

By control head,I'm talking about the actual dials you turn to control temp,fan etc.Most older model vehicles had vaccumn lines running out the back to control the dampers opening and closing.Newer models are mostly eletrical.Power from the head to the damper needs to be checked.If it is vaccumn controled,chek for leaks under the dash as well as in the engine compartment.
Good Luck,
Paul

The Control Head is all electronic/electrical. I took it apart and cannot see any obvious damage. The wires go into a larger harness.
Since I do not have a Manual, I would like the know the following:
-Are the flaps inside the Air Exchanger box all vacuum operated or by electrical motors?
- Does the Control Head module control the Vacuum modules directly or is there another Electronic module in between?
I have taken the dash apart and cannot see or hear any vacuum leasks.
The Control Head consists of 3 controls. The Fan Speed, On/Off, etc control, the Air Direction Control (upper, lower, defrost, etc.)control and the Temperature control. The Temperature Control is the one that has NO effect on anything and it should control the Air flow (Cold or Hot) per the Temp setting.
If the flaps are controlled from the Control Head, then I can buy and replace this module.

Thanks
Tony

I tried a "good" working control head and there is NO change. I assume that the problem is in the ACTUATOR that moves the flaps)itself. Can anyone direct me to where I can get a "service manual" that shows what pins of the control head control what actuators for which dampers and where the dampers and actuators are Physically located?
Thanks,
Tony

Please respond as soon as possible.
Thanks

Hi Tony,

Remove the under dash panel on the right side of the vehicle and look at the HVAC case for an electric actuator motor for the temp. door. It will have an electrical connector, possibly a vacuum hose harness and a plastic arm that connects to a threaded silver rod that is connected to the temp door also.

You may have to remove the glove box to see everthing.

Has the rod become disconnected from the actuator motor?

GM uses a Programmer to control air distribution and temp. control. The motorized actuator is mounted on or in this programmer box.

If the rod is still connected to the actuator motor the motor may have quit or gears inside the motor case have stripped out and the door position can no longer be controlled.

Let me know what you find, please.

Roger

Hi Roger,
I will do this on the weekend. However, when I plugged-in the "new" Temp Control module, I heard a "thump" from the area where the heater core is located and then nothing...hot air thru the heater core was blowing in the cabin.
My guess is that the "actuator" is likely shorted and momentarily changed the damper setting and then likely damaged the Temperature control head. Since I am not familiar which activator does what function, but I know how to trace electrical problems (I am electronics engr), do you have any idea where I can get my hands on a "schematic diagram" of the wiring and trace which actuator is giving me this problem?
Thanks,

Tony

Paul must have thrown you off track with his ideas of control head suspicions. I don't agree with him at all.

The programmer box I spoke of contains the vacuum controls to direct air delivery as demanded by the control head settings.

However the temp door has to have a motor to move the door and stop when told to. A vacuum actuator would only go full range.

A wiring diagram in my opinion would be over kill as we are interested in just the temp door motor. There is no problem with the air delivery, only the temp of the air delivered.

See if you can find the programmer attached to the HVAC case. Hopefully I've described it well.

The skeleton hiding here is whether you can buy the temp door motor without buying the whole programmer assembly. It's likely a Dealer Only Item so you may choose to shop salvage parts also.

Roger

Roger,
I am in your camp! The control head has the microprocessor and the temp sensor that controls all the functions ( I took it apart). I followed your suggestions and took off the glove compartment and I (THINK??) I see what seems to be a "stepper motor" on TOP of the Heat Exchanger Box. I think it may have shorted and now is stuck in the Heat Position.
The problem is that there is NO space to remove it. seems to me the whole box needs to come off or take the dashboard top off...somehow??
The circuit diagram would allow me to measure the impedance or apply external voltage to see what the motor does and confirm that it is the stepper motor. I would hate to take apart the dasboard to find out it could be something else.
The stepper motor makes sense since it rotates in small steps and when the temp reaches a certain setting, it feeds back to the micro and it stops the motor. As the temp varies from the setting, the micro tells the motor to rotate to give more heat or cold.
If the motor is indeed shorted, I am afraid I blew the replacement Temp Control module on the dash that contains the electronic controls.
Should I give up?? Dealer wants about $900 to repair??
I appreciate yur advice.
Thanks,

Tony

The programmer assembly can be removed from the HVAC case...usually has three mount screws. You'll of course want to disconnect the silver rod for the temp door first by releasing it from a plastic U-shaped retainer on the motor arm. You should not have to remove the top of the dash. The programmer should not be that deep.

These little motors occassionally short out. The failure is more often a stripped gear (plastic) inside the motor case. Gears are not field serviced.

How certain are you of toasting the Temp Control on the dash?

I wouldn't give up and go to the dealer yet. You can get salvage parts to control cost. A programmer is pricey! You can do this.

When you get the replacement Temp Door motor you'll need to calibrate it. This is easy. With your new parts mounted in place and the key ON, set the Temp Control to full HEAT. The motor will move the full extreme of the sweep that would pull the Temp Door rod toward the rear of the vehicle. When the motor stops gently pull the Temp Door actuator linkage toward you until you feel resistance telling you the door has moved against it's stop. While holding the door gently against the stop snap the linkage rod into the retainer arm on the motor. Your finished. Reassemble trim and glove box as needed.

Roger

Tony,

One more thought is to look at the section of the HVAC case the programmer is mounted on. If it appears unhandy to dismount the programmer to access the Temp Door motor perhaps a section of the case shell will come off with the programmer still attached and you'll be able to service it that way, reassemble and calibrate the motor with the door linkage as I described earlier.

Just a thought,

Roger

Roger,
Thanks for your inputs. I will try it this weekend.
If it does not work, I am sure the Dealer will gladly take my $900 to repair it.
I am not sure that the Temp Control Module is fried. Since I do not have any schematics or connection diagrams, it is hard to trace the connections and test them. I am into electromnics and that "stuff" I know pretty well but without a schematic, it could take me days to trace the wires, etc. specially when the motors and actuators are not readily visible.
I will keep you posted.
Thanks for your help.

Tony

Tony, Please advise your email address and I'll try and get schematics to you. If a fax works better for you, please advise the number.

I'm headed for the data base right now to see what I can find.

Roger

Hi Tony,

I have some good stuff for you! Schematic and drawing.

Instructions for replacing the Air Mix Door Actuator does call for removal of the instrument panel screws/nuts and roll back instrument panel after loosening it for access. :(

Roger

Hi Roger,
My Fax is [redacted] and my email address is [redacted] .
I took apart the Dash, the Glove compartment and I can see the Air Mix Compartment (semi round black plastic box with other plastic ducts from it).
It looks like there is a small flat motor (one inch thick?) mounted on top of this semi Round Black enclosure that contains the heater Core and the A/C Evaporator coil. It seems that the motor is held in place by 2 vertical 7/32 screws. It seems to have a one half inch square vertical hole at one end of the Motor module. There seems to be a round metal rod from the square hole that goes vertically into the plastic enclosure. The motor has a 6 pin connector with 5 wires from it. The 5 wires, I traced to the connector that plugs into the Temperature control module that mounts on the dash.
In tracing the wires, 2 wires measure 0.017 ohms which is likely a "short" while the other 3 wires seem to be "open", no connection to anywhere in the motor or ground (car chassis).
The space around that motor is "tight"! I believe the construction is such that IF I remove the 2 screws, I may be able to lift that motor about one inch and remove it. To reinsert it, I think it is a matter of lining the square hole over the square portion of the round shaft.
This has become a "challenging project"...my wits against GM...
Please feel free to send whatever info you have to the fax machine or my email.
Where are you located?? Have you worked on these type of problems before??
Thanks,

Tony

Tony, I am in Arcadia, Oklahoma about 22 miles NE of Okla City.

Yes I worked for GM Dealerships for over 25 years.

I'll send you a FAX. I believe it will be better copy.

That flat motor you describe is the culprit.

Roger

Roger,
Thanks. It is tough to find the problem without a schematic. It is like finding a street without a map.
My fear is that IF the motor is "shorted", it may have taken out the Temp Control module since the Integrated circuits in the module do not handle those high currents well and die! On the other hand, if the motor has gone "open", then the Temp control module may still be OK.
After I take it out, I will check the motor carefully as I am inquisitive as to what happened. To remove that motor one needs very, very small hands and fingers...It is even hard to find a 7/32 wrench with a long handle...I finally found a set at Sears that has a 7/32 box wrench...It is NOT metric, for sure.
My next opportunity to work on this is Friday. I will keep you informed, if you like.
Thanks,

Tony

Sure, I want to help and I stay sharp by your feedback of the repair process.

I have small hands. God blessed me with genuine technique in working hard to access places. My time in person is $80/Hr. You would shiver at the sight of some of the vehicles I've had apart. Some I won't let owners see because they would never believe I could get it reassembled rattle free.

I'm trying to save you enough money you'll be proud of yourself. Paying retail is hard on us all. The only thing I let others fix is a transmission.

Roger

OK..I will give you feedback.
I went to Engineering School and learned about alot of things. When I used to have time, I used to do nearly all the work on my own cars, including valve jobs, brakes, etc. I also do plumbing, some carpentry, electric stuff, etc...
I still do some just to keep me challenged. I also have a BIG problem when a Dealer wants $900 to change a motor. Even at $100 per hour, a good mechanic with experience should be able to change it in less than 4 or 5 hours, no???
By profession, I am in Electronics...In fact we designed the first all transistor AM/FM stereo radio for Chrysler Canada, back in 1968.
The company I work for now, we make the Audio Processor Integrated Circuits that go into all the Bose radios for all the Automobiles with Bose systems.
Thanks

Tony

Thanks for the personal background information. I agree that $900 is too much to throw down for the job in question.

I haven't looked to see what the charge would be in OKC.

Roger

General info:

Mitchell 1 Auto Repair Data Base Estimater says the flat rate time to replace the Door Position Sensor is 5.2 hours.

Warranty time is shown to be 2.1 hours.

There is quite a difference in alloted time to do the job based on the in or out of warranty status. This is why mechanics drink and shake while yet only in their twenties :)

One can believe a dude that knows the tricks could do the job in about two hours and break even. I doubt it.

Roger

Hi Roger,
It has been several days since we communicated on the 1998 Olds Bravada.
Well, I changed the Temperature Control Module on the dashboard and finally changed the Temperature Actuator module that sits on top of the Heat and AC exhcanger and the problem remains! As soon as I connect the Actuator Module, it operates and the rotates the damper to the end of its travel on the "HEAT" side.
The schematics you faxed to me are useful but the fax copy ot the schematic page is not very legible.

I now think that one of the temp sensors or solenoids must have a problem that causes the Actuator to rotate to HEAT. The Temp controls have no effect.
If possible, could you refax that one page of the schematic on a the highest resolution possible?
In case you need it, my Fax nmbr is [redacted] . Alternatively, let me know how to get a hold of the book it is in and I will try to get it on line.
Thanks,

Tony

I'm stunned at this outcome. I would never have anticipated such results.

How did the electronic actuator respond to the calibration step?

I'll get you a better copy of the schematic today.

Roger

I have faxed about ten pages of data right out of an Olsmobile Shop Manual.

It would be great if you had access to a GM TECH II Scanner to read body codes.

I'm thinking you may glean something from these pages and set a path to fix it.

Hope it's not too much info,

Roger

Roger,
Thank much! I received the 10 pages and seem to be exactly what I needed. I have not had a chance to study them, but at first glance the info gives me the necessary info I need to understand how it works and what sensors control what.
The voltages on the pins of the Actuator Module indicates that the module is working properly, as it is driven to "heat" position.
The fact that the Temp Control has NO influence on the position of the Actuator, indicates (to me, at least) that there is a "faulty" sensor that drives the unit to "heat" mode.
I will study it and will keep you posted. This is good Engineering problem to solve...for me.
Thanks again.
Tony

Tony, You are welcome. The info was made available to us from a Cadillac dealer in OKC, OK from where I retired. They are a former Oldsmobile dealer and still had the shop manuals.

I too will look over the info as things slow down a bit and see what triggers the system to fault toward heat.

The in-car temperature sensor above the drivers door could factor here as well. It samples the interior air for comparison with driver selected set/desired interior temp. on the control panel.

Roger

Roger,
Thanks again.
I will look at it this weekend and let you know what I find.
Unfortunately, I do not have much spare time, but this Bravada is a "spare" that I use to haul things around. It is in very good shape and has only about 68K miles.
If I sell it, I get very little, so I decided to keep it. This problem has me a bit baffled, but my engineering curiosity is getting the best of me. If I had the proper documentation like you sent me and some time, I know I can find the root cause. It is just a matter of spending a bit of "dedicated" time.
Thanks for your info.
Tony

When you can, bring me up to speed with your findings.

Roger

I learned yesterday not to ever connect the electronic actuator electrically without first installing same in it's proper place on the HVAC case.

Connecting the actuator electrical connector and testing to see if it works before you install it will destroy the actuator and void the warranty!

Roger

Hi Roger,
Thanks for your input.
I opened the old actuator to see why it did not work and understood very rapidly by looking at the construction that it needs to be in place to avoid damage.
When it is in place, the flap in the mixing chamber restricts the rotation. If not in place, there are "stops" on the plastic housing that restricts the rotation, but it allows more than the flap.
The torque is very high. There is a very small DC motor with a worm screw gear and a number of "reduction" gears. It must be around 50 to 1 reduction so the torque is quite high at the flap control end.
I tested the old one and seems to be fine, so I purchased the new actuator for nothing...
The unit still moves to the "heat" position. After replacing the Actuator and the "control" unit on the dash, it still behaves the same way.
My next thought is to look for shorts or open connections and possibly the various temperature sensors, to see why the temp controls have NO effect on the position of the actuator.
I just need some time.
The schematics you sent are very helpful Thanks again. Unfortunately, the documents do not explain the inside of the "electronic control module" to allow me to figure out the actual workings and the reason it just moves to heat position and the temp control has NO effect.

Thenks for your help. I will keep you informed on what I find.

Rgds,
Tony

Do you have access to a shop manual? The pages I sent are from a shop manual printed by Helm, Inc. (www.helminc.com) It's the one the dealer uses. Pricey!

I copied only a fraction of the HVAC section. I tried to focus on the temp door actuator. There is so much more I'm embarrased to admit it. I was pushing my welcome to copy what I got.

Roger

Roger,
Thanks for the source info. I do not have a manual, but I can get one. They have so many on line that it is difficult to choose.
I appreciate the copies you sent and the big schematic page is great. Once I get some time to work on it, I will gigure it out.
I am busy with work and not much time for my Bravada. I have 4 other cars that just sit around.
I have a 1975 Benz 450 SL I am going to try to sell on ebay, I guess. I put 250 miles in 5 years!!???
I will keep you posted.

Thanks again,

Tony

I'll be waiting for your progress update.

Thanks,

Roger

1998 Oldsmobile Bravada Electrical / Lighting Systems   

The entire electrical system failed. The car started and ran normally and as I backed our of my driveway, everything shut down. Even the garage door opener does not work. Is there a master fuze link that may have opened up? I checked the under hood fuze box and no fuzes appear to be blown.

do u have power at inside fuse block
also when turn key on does any lights come on

I found out that the problem was at first apparently a bad battery because I could not measure voltage at the screw terminals of the side-terminal batterr. So I disconnected the terminals, but then the batter read okay (measured at the female threads of the battery itself. I cleaned the flat terminal connectors with baking soda, reattached and everything is now okay. Really wierd. There was no corrosion, leakage or anything, and the connector screws were tight originally. Thanks for your help.

the best cleaner for batteries is vinegar