Author Topic: 1991 Olds 98 auto temp control  (Read 1143 times)

Jim Tighe

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1991 Olds 98 auto temp control
« on: February 05, 2005, 12:30:45 PM »
I know this is not a Cad question, but my 91 Olds 98 is very similar to some contemporary Cads, so I will ask you Cad folks.  The old beast has the "auto temp control" heating/AC setup, which will not allow the blower to kick in on cold days until the car has been driven anywhere from 20 minutes to half an hour.  The heat is there, but cant blow it out the defroster.  Owners manual sez there may be "up to a 4-minute delay" when weather is cold.  So, it seems that even a new one of these would not blow thru the defroster right away, which seems stupid.  And, now, with years and lotsa miles on her, "4 min" have expanded.  I bought her for a beater and cant sink lotsa $$s into this.  Once the thing comes on, it works fine.  It will come on more quickly in northern Ohio cold if I fire it up and let it idle for awhile, shut it off, do the same again, and then drive off.  But that aint much of a solution.  Any ideas?  BTW, I do own a Cad, too, so am not a complete interloper.  I tried the Olds Club site with no luck.  Thanks for any ideas.  Jim, in Galion, Oh.

Michael Stamps 19507

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Re: 1991 Olds 98 auto temp control
« Reply #1 on: February 05, 2005, 12:49:44 PM »
On the older 472/500 engines I am used to there is a temp sensor on the engine to keep the blower off until the engine is warm.  You can ground that switch out and you get blower when it is cold.  Might be a stab in the right direction for you.

Stampie

Rusty Shepherd CLC 6397

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Re: 1991 Olds 98 auto temp control
« Reply #2 on: February 05, 2005, 05:15:32 PM »
Those systems rely on a sensor in the cooling system to dictate when the system delayed and began operating on cold start-up. This was to prevent cold air from being blown into the passenger compartment on cold start-up. I dont remember what the minimum temperature for blower activation is, but its significantly below normal operating temperature and not too far above cold on the gauge. If your Cadillac is air conditioned and later than a 1963 model, it has Automatic Climate Control with the same delay as it was a feature of the system from its introduction in 1964. You say the heat is there, but are you sure? I think a gauge package was optional, not standard, on the 91 Olds 98, so you may just have a hot light and no way to know when the engine temperature climbs above cold or reaches normal operating temperature.  If there is no radiator thermostat or there is one thats stuck open, it may be possible that it takes 20 minutes to reach the minimum temp. needed for blower operation after a cold start-up on an Ohio winter morning.

Steve Crum 20999

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Re: 1991 Olds 98 auto temp control
« Reply #3 on: February 05, 2005, 06:31:52 PM »
On my 92 Eldorado, The blower delays until the engine temp is 100 degrees. I know this because when I leave work for home at 2:00am, the engine hits 100 and the blower kicks in at about the time I reach the 4 corners. Then I can mash it going onto the 4 lane! (the Eldo has the spiffy LED dash display).

Jim Tighe

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Re: 1991 Olds 98 auto temp control
« Reply #4 on: February 05, 2005, 07:08:13 PM »
Thanks, fellas.  I say that "there is heat" cause you can feel it coming up through the defroster vents at the base of the windshield once you get moving, even tho the blower is awol. So, I believe the engine thermo is working. Over the years I have had several Cads from 66 thru 76 with the accursed "climate control" monster, but seem to recall that one could get the defroster to blow across the windshield even tho the system wasnt putting out warm air yet.  My 79 Lincoln will do that also. Even cold air will help de-fog the windshield.  Give me the simpler, pre-"automatic" things anytime.  Course when yer buyin an old beater you cant specify the options U want.  It is not a bad ole car; just this one glitch.  My 64 Cad sleeps away these awful Winters in the garage, and waits for Spring, unconcerned about any of this.  BTW, there is also a "four corners" here in Galion. Thanks for your suggestions.  Any one else?

Rusty Shepherd CLC 6397

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Re: 1991 Olds 98 auto temp control
« Reply #5 on: February 06, 2005, 05:20:16 PM »
I definitely prefer the manual systems, too, with complete control over temperature, fan, and air discharge. Youd think that after forty years they would be perfected, but there are still certain conditions in which they just dont work well. The newer ones have solar sensors which seem to make one of the most annoying traits even worse: on a cold, sunny day,the sun causes the unit to cut the heat and/or start cooling so your feet, which are in the shade, get blasted with cold air and you have to run the thermostat way up to overcome it.
When Cadillac introduced Comfort Control in 1964, the ads said that a new owner could set the system once and never have to touch it again. Well, thats still not the case.

Jim Tighe

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Re: 1991 Olds 98 auto temp control
« Reply #6 on: February 07, 2005, 08:59:03 PM »
Amen, Rusty!!! Why needlessly complicate something so simple as selecting how much heat you want to blow where and when??  If a driver cannot determine something as elementary as this, what business has he or she driving in the first place??

 



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