HELP: Installing Electric Temperature Gauge in 1992 240

  • Thread starter Thread starter Fort Worth
  • Start date Start date
F

Fort Worth

My engine temperature gauge on the dash of my 1992 240 does not work on a
regular basis - in fact, I would be surprised if it's accurate even when it
does work...

I was advised by my local Volvo mechanic I should probably install a new
temperature gauge, but it probably wouldn't be worth the expense to change
the one out in the instrument panel if I just needed one for
functionality...

He did advise it would be electric so I could purchase a new one and just
wire it into....

That's my question. Where do I wire the thing? I looked through my Haynes
manual but couldn't find much information about the temperature gauge. I
pulled the instrument panel out to see if I could figure out where current
one runs but I couldn't determine which connections were for the temperature
gauge.

I would like to get a small gauge and just install it on one of the empty
squares by the radio.

Any feedback would be appreciated. Any time I've needed help you all have
always been very responsive and supportive. Thank you to all of the Volvo
enthusiasts out there that make up this delightful group...

Ray
Fort Worth

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Fort said:
My engine temperature gauge on the dash of my 1992 240 does not work on a
regular basis - in fact, I would be surprised if it's accurate even when it
does work...

I was advised by my local Volvo mechanic I should probably install a new
temperature gauge, but it probably wouldn't be worth the expense to change
the one out in the instrument panel if I just needed one for
functionality...

He did advise it would be electric so I could purchase a new one and just
wire it into....

That's my question. Where do I wire the thing? I looked through my Haynes
manual but couldn't find much information about the temperature gauge. I
pulled the instrument panel out to see if I could figure out where current
one runs but I couldn't determine which connections were for the temperature
gauge.

I would like to get a small gauge and just install it on one of the empty
squares by the radio.

Any feedback would be appreciated. Any time I've needed help you all have
always been very responsive and supportive. Thank you to all of the Volvo
enthusiasts out there that make up this delightful group...

Ray
Fort Worth
Click to expand...

If you install a new gauge, it would be very unlikely to be compatible
with the existing sender. The sender is under the intake manifold #3
runner, look for the yellow wire.
 
Thanks Mike.

I found the sender. Thank you for your feedback and your help.

Do you know of a way to test the resistance in the sender to make sure it's
working properly?
Is there a way to remove or ground out the yellow wire to see how the
existing temperature gauge responds?

Thanks again...

Ray

x-- 100 Proof News - http://www.100ProofNews.com
x-- 3,500+ Binary NewsGroups, and over 90,000 other groups
x-- Access to over 800 Gigs/Day - $8.95/Month
x-- UNLIMITED DOWNLOAD
 
Larry said:
The gauge and sensor are probably both good, there is a "compensation" board
on these cars that always goes bad (it's designed to make the gauge lie about
the temperature anyway) that can be bypassed. IPD has a kit to do that:

http://www.ipdusa.com/ProductsCat.aspx?CategoryID=1455&NodeID=4668&RootID=629
Click to expand...


*That* explains why I noticed my temp gauge never ever ever swings high
or low from the 9:00 position, even if the A/C is kicking on and off
in hot weather.... So if it did actually start to move higher, how
hot would the coolant temp be ?
 
*That* explains why I noticed my temp gauge never ever ever swings high
or low from the 9:00 position, even if the A/C is kicking on and off
in hot weather.... So if it did actually start to move higher, how
hot would the coolant temp be ?
Click to expand...

I was in a Volvo specialist the other day where they were taking an
engine out of an V70 that had cooked. Apparently the temperature guage
moved rapidly upwards when one of the hoses blew off and dumped the
water. The driver saw this and started to slow down but then the guage
moved back downwards.

They tell me that the ECU interpretes the temp reading and then
displays it on the dash which is why it never moves. However, if it
rises too high then the ECU can decide that the sender is faulty and
just ignore it returning the guage to normal. Result - cooked head!!!!

Sean
 
Sean Nugent wrote:

They tell me that the ECU interpretes the temp reading and then
displays it on the dash which is why it never moves. However, if it
rises too high then the ECU can decide that the sender is faulty and
just ignore it returning the guage to normal. Result - cooked head!!!!
Click to expand...

Morons. Isn't the whole point of a temperature gauge to see the
small fluxuations and alter your driving accordingly? Especially
in an emergency situation like you posted, you WANT the gauge to show
that it is climbing fast and not going down.

That information would have been enough to save that engine.

Funny, though - it would cost them less to make it the old way
and it would be more reliable.
 
As everyone has already pointed out, 240 temp gages are notorious for
problems, but most (probably 98%) of the time it's the temp comp
board, and that usually can be fixed just by cleaning the contacts.
In over 20 years of driving 240s, and now have 4, have only replaced
one temp gage, have replaced lots of temp comp boards (before I found
out about cleaning), and for past several years have revived most just
by cleaning and dielectric grease. If you do need to replace gage,
used OEM are generally around $20. The test for the gage is easy and
can be found in Bentley manual, which is a must for 240 owners.
 
Joseph said:
Morons. Isn't the whole point of a temperature gauge to see the
small fluxuations and alter your driving accordingly? Especially
in an emergency situation like you posted, you WANT the gauge to show
that it is climbing fast and not going down.

That information would have been enough to save that engine.

Funny, though - it would cost them less to make it the old way
and it would be more reliable.
Click to expand...

Actually it costs more the old way, but for a totally different reason.
The old way, people notice the small fluctuations, then complain to
their dealer who just replaces some parts under warranty to make the
person happy. This is paid for by Volvo. The new way, they don't
notice the fluctuations, so they don't complain, and therefore Volvo
doesn't have to pay anything.

In this particular case, the check engine light should have come on with
a temperature sensor code. Which goes to show you, if the check engine
light comes on, it could be something not worth worrying about, or it
could mean that your engine has 15 seconds to live!
 
David said:
*That* explains why I noticed my temp gauge never ever ever swings high
or low from the 9:00 position, even if the A/C is kicking on and off
in hot weather.... So if it did actually start to move higher, how
hot would the coolant temp be ?
Click to expand...

I think it's more a time/temperature thing, if it's running slightly hot for a long
enough time, the comp board will allow the gauge to show it. This was done because so
many folk will bring the car in for service if the needle is ever above it's "normal"
spot, so the comp board lies about the current temperature. I've noticed, now that my
car has the comp board yanked, that when I hit the freeway offramp and stop, the gauge
will go up to about the 10:00 position for about 30 seconds before going back down.
There must be some threshold, tho, 'cos my car was always rock solid at 9:00 with the
comp board, and actually runs slightly higher than that normally with the board
removed. On cold winter days the temps run at about the 8:00 position.

Newer Fords with temp gauges don't even have analog senders. There are two temp
switches on the engine, one that sends the gauge to the middle, and one that sends it
into the red.

The comp board's connections, as found on the 240, are really a work of crap. In my
family there are five 240s ranging from an '86 to a '92, and they have all had comp
board problems.

When my mom's '86 was new, they and a couple of friends were driving across the desert
when the comp board decided to act loopy and show an overheating condition. Since
they were miles from anywhere, they opened the windows in 110 degree heat, cranked up
the heater to help cool the car, and kept going. By the time they go to town, the
70-something friend in the back seat suffered from heat stroke and they got to spend
the rest of the day in the ER. Of course, nothing was actually wrong with the engine
and we weren't yet aware that the temp gauge lies. This is why I prefer to remove and
bypass the comp board rather than try and fix it, I'd much rather know what's going on
now and not trust a device that's sole purpose is to lie.
 
Hi Fort,

The board, as far as I know, never fails. It's always the contacts that do.

However, I prefer to know what the temps are, so I jumpered my board out.
As I recall, it takes two jumpers. If you can follow the traces on the back of
the circuit board, it should be easy to figure out. I did publish on usenet
about 15 years ago the pins to jump. :) Maybe google groups would still have
it...

Best,

Larry
 
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