Temp gauge up and down with alarm and check
 

I had too replace a broken belt after the alternator seized. at the time of the break- engine got hot and went into alrm until I was able to drive four block home.
Now that all is replaced I still have a problem. the water level alarm, engine check light, audible alarm pulsing and the temp meter in going to fluctuating low to max. The water is up to the neck of the upper tank. scratching my head on this problem. 99 freightliner isb 5.9

Do you know your chassis build date ?
I have to ask because , there was a wiring harness and gauge package running change in the Freightliner 98/99 chassis production .
Some late 98 chassis , sold as 99 coaches by the manufacturers will have a dash gauge package that's like the first picture , those 99 chassis built after Jan 4,1999 will have a gauge package like the second . All the testing info I have for gauges is for the second photo.
Note : If during the overheating , the coolant actually boiled , both the sensors ( temp & level )could be cooked.

Hi Skip, It is the one with the gauges to the right. the Not sure if it boiled since I only drove it for about 4 or 5 minutes down the street and returned immediately. Any thing is possible.

[QUOTE=ladagobago;5494931]Hi Skip, It is the one with the gauges to the right. /QUOTE]

OK , I'm not getting your " to the right " :confused:

Is your gauge package all in the one panel , like the top photo ; or individual round gauges like the bottom photo?

Or can you find a decal near the drivers seat, low on the wall that gives the production month.

I suspect the overheating caused an air pocket in the cooling system, thus the gauge swings. The coolant tank must be full and coolant in the overflow plastic tank.

[QUOTE=Skip426;5495562]Sorry, the pictures were left to right in my browser.
Mine are the round individual gauges.

Ok then this will be the testing info you need .

Thanks Skip, So what I am getting is at ignition on the standard lights PLUS the water level, check trans. as stated the water is at the top of the tank and when I take the cap off coolant drips out. I don't get why the trans light is on.

Top of tank of the rad ? or top of the surge tank ?

My side rad chassis has the low coolant sensor in the surge tank : but rear rad maybe different .
Any codes in the trans controller?

this is a rear rad and the rad tank on top is full . the surge tank does not have a sensor

Update on gauges
 

After a while I figured it out. The gauges are supposed to operate as follows: When turning on the key, the normal action of the gauges should be to go up and then return to their normal position just to show the are connected and operating. In my case the temp gauge went to max and the red image on the display shows as well as the ck eng. This would mean that the temp gauge was not getting a signal.
So I went back to find the temp gauge and put my finger on it. The connector was not there. It was laying on the engine. My guess is that when the LN alternator froze and broke the belt, portion of the belt pull of the connector to the temp sensor. I thought the red indicator thing was a low water indicator but reading up on it it is the visual for engine heat.
thank for the reading material Skip. I help me to understand things. Engine in running nice and normal. Good thing. looks like we might see a hurricane soon and will have to reason to leave.

Nice find.....good reminder to check for other damage when a belt breaks.