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I’ve got a new one for everyone. This one is a FUN one.
We are discussing an 85/1 944, basically all original.
About a year ago, I replaced my failed thermo switch and got both fans running and cooling as designed. Last week while driving around I noticed the engine was running a bit hot. I live in gulf coast Texas so it’s HOT. When I got home, I noticed the thermo switch controlled fan was not running, leading me to believe the switch failed. Today, while diagnosing and fixing a few things, I determined the thermo fan does not come one when the car is at temp. I turn the AC on the the fans run as designed. While trying to get a better view of the thermo switch, I turned the headlights on to open them.
That is when I noticed the gauge temp pegged to cold. Almost like the gauge was unplugged. Turn the lights off, the gauge goes back.
I’m lost here! I am not an electrical person and have not done any electrical work recently that would have caused this.
Welp....I took the 3 grounds off, cleaned everything really well with sandpaper and wire brush. Nothing changed.
thermo switch fan did not turn on at temp, when I turn the headlights on the gauge temp pegs off and the left regular beam doesn’t work but the bright beam does.
thermo switch fan did not turn on at temp, when I turn the headlights on the gauge temp pegs off and the left regular beam doesn’t work but the bright beam does.
Did you test the thermo fan relay before assuming its the switch? The switch (sensor) may be working but the relay may not be.
Did you test the thermo fan relay before assuming its the switch? The switch (sensor) may be working but the relay may not be.
I haven’t gotten that far into it yet. Time was not on my side over the weekend. I will be doing that once I can find the time. Honey dos always come first.
Still haven’t gotten the time to test the relay yet. I fixed the driver side regular beam headlight. I rolled the fuses a few times, specifically the lower bank #1 and it’s now working.
The temp gauge still pegs cold when the headlights are flipped on and back when lights are turned off.
Does anyone have a diagram and maybe pictures of the grounding locations on the early cars? Specifically the instrument cluster ground if that’s I’ll I can get.
I do not have a diagram but there is a ground under the dash, by each headlight, and on each side near the strut towers. There are two large grounds on the bellhousing (one is the negative battery cable) just near the speed/ref sensors.
Definitely test the fan relay (walkthrough on clarks) and report back.
I’ve got a new one for everyone. This one is a FUN one.
We are discussing an 85/1 944, basically all original.
About a year ago, I replaced my failed thermo switch and got both fans running and cooling as designed. Last week while driving around I noticed the engine was running a bit hot. I live in gulf coast Texas so it’s HOT. When I got home, I noticed the thermo switch controlled fan was not running, leading me to believe the switch failed. Today, while diagnosing and fixing a few things, I determined the thermo fan does not come one when the car is at temp. I turn the AC on the the fans run as designed. While trying to get a better view of the thermo switch, I turned the headlights on to open them.
That is when I noticed the gauge temp pegged to cold. Almost like the gauge was unplugged. Turn the lights off, the gauge goes back.
I’m lost here! I am not an electrical person and have not done any electrical work recently that would have caused this.
08-26-2022, 03:29 PM
Well This is Different
