Chrysler Repair: Overheat, chrysler lebaron convertible, 1993 chrysler lebaron

Question
I am the one with the 1993 Chrysler LeBaron convertible. In the past I had the
clanking noise on start up-but this has not happened again. I have changed
the thermostat to a fail-safe. As long as I a driving a a reasonable speed, the
car does not overheat, but if I am in slow traffic-and the AC is on seems to
make it worse the car overheats.When I cut off the AC and try to speed up the
engine the temp continues to rise. Do you think there is a problem with
electrically between the AC and fan relay..is that possible the 2 are related or
aggravates the condition. I do not notice any oil in the coolant(unlike my
10987 van-you could see the slick and it was the head gasket). I just have a
sneaking suspicion it has something to do with the fan system. It there any
dianostic(s) that can be run to detect the problem. I would like to know what I
am talking about before talking to the dealer or to a garage.Are their any
engine codes in the switch on this model?  I will check for brake dragging and
also the sides of the radiator to see if they are both hot. What is the questions
related to steam if it is a head gasket-how do you check this? I thought there
is a device to insert into the radiator that test back gases from the exhaust?
How do you check for an air bubble and would this not have shown up a bit
sooner than afer the old thermostat was replaced. Thought car seems to sun
cool when there is no theromstat at all.  Any thoughts, suggestions?

Answer
Hi Marianne,
Those are several lengthy questions!
The most obvious question for you to answer is whether the fan is coming 'on' when the temp gauage rises over 3/4 or so, or when you see steam releases, for sure? If not, let me know and we can diagnose that specific problem. The only fault code for the system is a 35 which says the fan relay circuit is not working properly.
If so, then I would suspect the radiator is clogged.
Head gasket failure is seen either as white smoke in the exhaust at start up, or foam in the oil.
A radiator test usually is done with an exhaust gas tester which is an electronic test tool which is not economical for an individual owner to purchase.
Air bubbles should clear spontaneously by system design. Try opening the radiator cap and squeezing the top hose to clear it if it were there.
Also try using the heater as a secondary heat disposal mechanism when you are having an overheat situation if you can deal with the temporary cabin warmth.
Let me know about the fan function.
Roland