Temp gauge shows 0 all times

[dreager]

I read in a local paper how a thermostat built into block heaters can cause the in-dash temp gauge to show this function. Unfortunately the paper doesn't have an on-line edition to show entire article.

Fact is my gauge is dead and I wondered what other inline sensors would cause this, or is it just the gauge is kaput.Not much in the mood of ripping out dash.

[88PA]

Check the sending unit and go from there. I'm new to these Buicks but most temp. gauge sending unit is a resistive device that can go bad or come unhooked by recent work done in the area. I would go with after market gauge and sender before I would go into the dash, they never seem to be the same after...rattle...rattle.

[wrightz28]

Originally Posted by 88PA

Check the sending unit and go from there. I'm new to these Buicks but most temp. gauge sending unit is a resistive device that can go bad or come unhooked by recent work done in the area. I would go with after market gauge and sender before I would go into the dash, they never seem to be the same after...rattle...rattle.

Depends on the year:

Oler model use 2 to 3 temp related 'sensors':

A sending unit for the gauge
A switch for cooling fan operation
A ECT sensor for the ECM reference (sometimes fan op too)

Most newer models use the ECT for the ECM ref. which in turn relays the gauage reading info and fan operation.

[dreager]

Originally Posted by wrightz28

Depends on the year:

Oler model use 2 to 3 temp related 'sensors':

A sending unit for the gauge
A switch for cooling fan operation
A ECT sensor for the ECM reference (sometimes fan op too)

Most newer models use the ECT for the ECM ref. which in turn relays the gauage reading info and fan operation.

'92 PAU 300km
Thanks for replying,

Any location on that sending unit ? I'm assuming the switch is at/near fan ?
All help appreciated.

[HotZ28]

I assume you have a 92 PA . It's best to include that in your first post, thread title, or in your signature! If in fact it is a 92; The "one wire sensor" is the sending unit for the gage, located on the back side of manifold, passenger side, in the block. Usually when these fail, you would have a higher, or lower gage reading than actual temp; not "0"!

The "two wire sensor" (more commonly referred to as the CTS) has a 5v reference from the PCM and variable voltage feedback to the PCM, based on coolant temp. The PCM provides a ground for the coolant fan relay, when temp dictates.

[dreager]

[quote=HotZ28]I assume you have a 92 PA . It's best to include that in your first post, thread title, or in your signature! If in fact it is a 92; The "one wire sensor" is the sending unit for the gage, located on the back side of manifold, passenger side, in the block. Usually when these fail, you would have a higher, or lower gage reading than actual temp; not "0"!

The "two wire sensor" (more commonly referred to as the CTS) has a 5v reference from the PCM and variable voltage feedback to the PCM, based on coolant temp. The PCM provides a ground for the coolant fan relay, when temp dictates.


Thanks Hotz as always you're there.
You're saying I may need to replace the CTS sensor then which I'm assuming is a dealer part? Will a Lesabre part fit as there are prolly more of them knocking around? Waiting for cold snap to end here and will keep you posted.

My defroster/locks/seats still working since cleaning relay!

** BTW I didn't know about the signature bit Thanks, I did that !

[Blue Bowtie]

Is it a digital display or analog gauge? If it's analog, does the indicator needle sweep toward full scale while the engine is cranking (bulb test position of the switch)? If not, it may be an instrument problem.

[HotZ28]

Thanks for posting the year & model of the car in your signature! Now you don’t have to remember to put the year in your post every time, and in turn, we don’t have to guess what you have.

Actually, what I was trying to say in my previous post was; I think you may have a bad IC gage, however, you should replace the “one wire” sensor and see what happens. The one wire sensor is very cheap (less than 10 bucks) and available at all major part outlets. Looks kike the one in the pic below.

My defroster/locks/seats still working since cleaning relay!

Good job! You did all the work, all we did is point you in the right direction!

[dreager]

Originally Posted by Blue Bowtie

Is it a digital display or analog gauge? If it's analog, does the indicator needle sweep toward full scale while the engine is cranking (bulb test position of the switch)? If not, it may be an instrument problem.

It is anolog and no sweep, no movement whatsoever.