Weird heating problem
So to begin this is a 97 bonneville ssei with no mods or anything and about 275k km on the original motor/tranny
So here is my problem. No heat! So when I turn the temperature up to 32 C it blows cold air out. If I turn the temperature to 15 C it blows hot air. The control board has been replaced once and I am not quite sure what the issue is.
Now when I turn on the car the temperature continues to blink for like 3-5 minutes, but only when I start it up.
I disconnected the battery to see if it would reset it, but no luck.
It puzzles me that when I turn it onto the "cold mode" (as in 15C) it blows hot air, and then when I turn it to the "hot mode" (as in 32C) it blows cold air. If I put it one notch above the 15C which goes to 19C it blows out warm air, but more to the cold side.
What is my problem here, and what can I do to fix it?
Thanks
So here is my problem. No heat! So when I turn the temperature up to 32 C it blows cold air out. If I turn the temperature to 15 C it blows hot air. The control board has been replaced once and I am not quite sure what the issue is.
Now when I turn on the car the temperature continues to blink for like 3-5 minutes, but only when I start it up.
I disconnected the battery to see if it would reset it, but no luck.
It puzzles me that when I turn it onto the "cold mode" (as in 15C) it blows hot air, and then when I turn it to the "hot mode" (as in 32C) it blows cold air. If I put it one notch above the 15C which goes to 19C it blows out warm air, but more to the cold side.
What is my problem here, and what can I do to fix it?
Thanks
ok, so I understand you correct, you get cold air when it is set to 32C, and hot air when it is set to 15C, and warm air in between?
Which control board was replaced? Was it the one in the panel with the buttons, or the one in the programmer in the dash?
Almost sounds like some connections are backwards if I understood it right, but not sure what they'd be.
Get back to us on this, and we'll help you get to the bottom of this.
Which control board was replaced? Was it the one in the panel with the buttons, or the one in the programmer in the dash?
Almost sounds like some connections are backwards if I understood it right, but not sure what they'd be.
Get back to us on this, and we'll help you get to the bottom of this.
Yes cold air when set to 32C and hot air at 15C....Anything between that is pretty much cold.
The actual panel was replaced. Like the one with all of the buttons on it. The board that you change the temp, fan speed, location of blower, defrost etc.
It isn't wired backwards, as it had been working since the day I bought it, just last week it started to do this.
thanks
The actual panel was replaced. Like the one with all of the buttons on it. The board that you change the temp, fan speed, location of blower, defrost etc.
It isn't wired backwards, as it had been working since the day I bought it, just last week it started to do this.
thanks
Joined: May 2006
Posts: 29,661
Likes: 43
From: Sheboygan Wisconsin






All I can think of is a short somewhere. Where that would be I have not a clue. I will admit, that'* a odd problem. Hmm, lets just throw out a idea or two here. Check the relays on the fire wall and see if one covers the heater. Perhaps a relay is stuck.
I read in the manual that there are different codes for why the temperature flashes. I have a scanner, just not one that can read those types of codes so I am SOL.
I may take it in to someone with a snap on scanner to see if they can get a code and then go from there.
I may take it in to someone with a snap on scanner to see if they can get a code and then go from there.
The blinking temperature display (blinking for 2 minutes on startup) indicates one or more stored fault codes in the HVAC processor. If I remember right, the '93 version does not require a scan tool to get the codes out; it'* a combination of button-pushing instead. Once you get it into diagnostic mode, it'll give you the codes and you then go look them up.
I'll run upstairs and go have a quick peek at the '93 book...
Okay, here we are. For the electronic controls as of the '93 model year, you get into diagnostics by turning the ignition switch to Run (but don't start the engine). The display should light up. Now press and hold the OFF and WARM (Temperature Up) buttons simultaneously. After holding them both in for about 3-5 seconds, the display should suddenly light up all segments as a self test. Release the buttons, and the stored codes should display, along with a Status Light display.
Error codes are either 2 or 3 digits. The 3-digit versions will have a 1 as the first digit (e.g. 115 instead of 15), indicating that it'* a history event rather than a current fault.
Status lights are displayed using the little fan speed indicator bars. You may see a snowflake symbol, or bars 1, 2, 3 or 4 lit up. Each bar has a different diagnostic meaning.
Press the AUTO button at any time to bail out of diagnostic mode.
Okay, see if the above gets you started, and if so, tell us what code(*) you get. If not, we'll need to wake up somebody with a '97 manual and get some better advice.
I'll run upstairs and go have a quick peek at the '93 book...
Okay, here we are. For the electronic controls as of the '93 model year, you get into diagnostics by turning the ignition switch to Run (but don't start the engine). The display should light up. Now press and hold the OFF and WARM (Temperature Up) buttons simultaneously. After holding them both in for about 3-5 seconds, the display should suddenly light up all segments as a self test. Release the buttons, and the stored codes should display, along with a Status Light display.
Error codes are either 2 or 3 digits. The 3-digit versions will have a 1 as the first digit (e.g. 115 instead of 15), indicating that it'* a history event rather than a current fault.
Status lights are displayed using the little fan speed indicator bars. You may see a snowflake symbol, or bars 1, 2, 3 or 4 lit up. Each bar has a different diagnostic meaning.
Press the AUTO button at any time to bail out of diagnostic mode.
Okay, see if the above gets you started, and if so, tell us what code(*) you get. If not, we'll need to wake up somebody with a '97 manual and get some better advice.




