Well-

I have a 93 bronco w/ a 5.0L motor. Recently, I have been having cooling problems. When I am driving my temp guage on the dash is jumping around like mad. My car hasn't acutally overheated and stalled, but it kinda makes me nervous.

Anyway, I have changed the thermostat and flushed the radiator w/ the Prestone flush fluid. I also changed the coolant temperature sending unit.

The problem is still occuring. Has anyone experienced this? If so, what was the actual fix?

Thanks,
Skip

 

Clean the terminals on the instrument cluster connectors and make sure the one on the sender is tight & clean.

 

Thanks for the tip.

Do I have to remove the entire instrument panel for this, or can I get at the connection from underneath?

I've never really done any electrical work. Have no experience with this kind of thing.

Thanks,
Skip

 

You have to pull the cluster out of the dash. Look up the procedure here. The hardest part will be popping the headlight **** off its stalk. Just don't break the tiny shift indicator cable sheath (automatic transmission only) when you actually pull the cluster.

 

That link takes me to a web page, but I cannot get past the page were I have to enter my engine size. Just seems to stick. Is that a web page for Chilton's guide or something similar?

I have a Chilton's, and looked through it. It listed the steps to remove the cluster, but not the steps for the temp gauge. Is it self evident after removing the cluster?

Thanks,
Skip

 

Yes, it's a Chilton's site. I've never had it lock up. I think there have been links to other versions of that site posted, so try searching if it still won't work.

You don't need to disassemble the cluster - just clean the terminals for the 2 big plastic wiring connectors. I said to also check the SENDER terminal - that's on the engine - not the gauge, but you can see the gauge terminals on the back of the cluster without opening it.

 

I have had this same problem on my '90. Most of the time guage was reading very cold, but bounced around alot. And one of the simplest things that I've done, was to crimp the the connector that slides onto terminal of the temp sensor on the intake manifold. Located pretty much right above #5 cylinder.

being loose on the terminal will give false signals like this.
Hope this helps

 

Ok

Now the situation has deteriorated. Unfortunately, the 93 is my daily driver. I know, I know. I'm getting another car to be my dialy in a week or so.

Today, once the temp gauge reached normal operating it kept right on moving until it was around the "a" in NORMAL. The issue now seems to be that the gauge is not bouncing around anymore. It holds steady at the high temp reading. Again, my coolant level is not low and no extra heat seems to be radiating from the engine after driving the five miles to work. Does this still seem like a gauge problem?

Someone suggested I by an after market gauge to attach to the wiring and see if it is giving me the same info as what the gauge in the cluster says. Is this worthwhile?

Thanks,
Skip

 

The "A" in "normal" is a little high, but it is normal...

These gauges are not perfect. But I would change the sending unit. It's on the intake manifold and very easy to change, 10 minute switch. Make sure to use teflon tape on the threads so it does not leak.

If you are not sure, hook up an aftermarket gauge.

 

I've been having problem similar to this with my temp gauge as well. As soon as I start my truck, the needle will point straight up, and then after the truck has had a chance to warm up, it slowly works it's way all the way to the right. But then, I'll hit a bump and it'll start to read normal like it's supposed to.

I'm not sure what to try to fix it. I've replaced the sensor on the top of the engine twice now, and that hasn't solved the problem. So, as soon as I get it fixed, I'll let you know what I had to do for my truck to see if it works for yours.

-Ferris

 

It is normal for the guage to go high when it is started cold, and then go low. It goes high until the thermostat opens, and then it will drop. Watch this next time you start your truck from being cold.

Also, mine, and seemingly everybody else's, fluctuates up and down slowly, like a cycle, while the truck is running. I don't know what causes this, it seems like the t-stat opens and closes or something. Or maybe that's how the gauge is. But I wouldn't worry about it. Mine has a new radiator, heater core, t-stat, sending unit, etc. etc. and it has always done this and not overheated. I did not replace these parts because of this though, the radiator leaked and the heater core was preventative. The sending switch was replaced because it died and the gauge didn't work. After replacing the sending unit, the gauge seemed to read "hotter" but the truck ran the same.