88 tc primary cooling fan coming on late

this thing has had this problem since i bought it.the fan dosnt come on until the temp gets right at the red. no codes ,new temp guage sending unit. i'm thinking maybe ect(coolant temp sensor) anybody have this happen?

Could be the ECT, they don't set a code unless they are real bad. Could be the hose fitting on the lower intake is clogged and the ECT isn't seeing the hottest temps. Could be a bad gauge, not uncommon, and they can be bad in either direction. Maybe the stat isn't opening all the way. A lot of people have had similar issues and their experiences are in the past posts.

My suggestion would be to see if it's really overheated when it hits the high point on the gauge. You could put a cooking thermometer in the radiator fill or use an infrared gun on the stat housing.

thanks, just had it all apart new timing belt,head gasket,studs,stat,hoses,water pump,hard lines,hd rad, intake is clear of debree.also idle gets eradic when it reads hot.i'll try the infrared tomorrow.

did infrared test on t stat housing and its 210f when the fan comes on. pos temp guage right at the red when fan comes on

210 is where the primary should come on