where the heck is the fuseable link under the hood for the aux cooling fan? 98 suburban 3/4 4x4.
fan no longer comes on.checked relay and looks good.fuse on the side of the dash is good.temp switch on engine block has x amount of ohms so assumeing it is good.

any other suggestions? not getting 12v to the leads going to fan.

98 should be a big maxi fuse but let me double check ok.

98 shows a 30amp fuse in the underhood fuse block/if that fuse is blown it will most likely be time for a new fan motor

the small 30 amp in the box under the hood is good.
inside dash fuse good also. ????

do you have to remove the grill to change the fan???

it is the easiest way that i know of.

and the fuse im talking about is the box looking fuse should be marked aux fan

maybe i missed one!

the fuse under the hood is in the fuse box,but it is a standard,small,yellow plastic blade type.

Does it say aux fan on the cover for that fuse.

yep !!

got to get this fixed before heading to Port A August the 2nd!!!!

Your aux fan should come on when your A/C compressor is on. Maybe the fan motor is Kaput!

it has always cycled on and off once it got hot enough, with the A/C on.had it for 9 years,and always did it.
just recently quit.makes a big difference when you are sitting still with the A/C on and it 100+ outside.

Was the fan cycling on and off? The Computer controls the fan relay, but if the A/C compressor cycles often also, the problem could be in with the A/C system.

a/c doesn't cycle that much,now that the freon charge is correct.
the fan has always cycled,more so in the the summer of course.
if i remember right,the fan would cycle whether the A/C was on or not.
truck has never run hot,even with the 195 t-stat in it.seldom gets over 170-180, except when sitting at a long stop.
Suburban is the 454 with all options including tow package and oil cooler,trans cooler.

Maybe this can give you an idea and help in the repair.

thanks,

going to take the fan out of the system and hit it with 12v.
i don't get 12v with the meter at the fan,but something upline may not be sending it.
need to locate the vcm!

Don't mess with the VCM, it's the vehicle(computer).

Just apply 12volts to the red wire going to the Fan Motor.

familiar with the computer,just meant that i bet it's the problem.
got fan to work with straight 12v to it!
the computer has been reprogrammed with a Hypertech system.
it askes if you have installed a 160 deg. thermostst or not,and i entered no.
should not effect anything,the program has been in the truck for years.
think the cheap way will be to bypass everything and just put a manual switch on the dash for the fan !!!

hold up, on that big block there is a sending unit on the side of the motor that sends a signal to the ecm to tell it to turn on the fan also, that could be bad.

The auxiliary cooling fan is controlled by the VCM. The VCM controls the ground path for the cooling fan relay. The relay consists of (1) underhood fuse block (2) auxiliary cooling fan relay (3) wiring harness and is used to control the high current flow to run the cooling fan motor. The VCM determines operation of the independent fans based on various sensor inputs.

The cooling fan is controlled by the VCM based on the following inputs:

• The A/C system

• The Engine Coolant Temperature (ECT) sensor

• The Vehicle Speed Sensor (VSS).

The VCM will turn the auxiliary cooling fan ON when any of the following conditions exist:

• Certain VCM Diagnostic Trouble Codes (DTCs) are set.

• ECT above 107°C (225°F).

• A/C head pressure above 300 psi.

Once the auxiliary cooling fan has been turned ON by the Engine Coolant Temperature (ECT) sensor, the VCM will turn the fan OFF when that temperature has dropped about 4°C (7°F). If the auxiliary cooling fan has been turned ON by high A/C head pressure, the VCM will turn the fan OFF when the pressure has dropped to 250 psi. The minimum ON time for the auxiliary cooling fan is 30 seconds.

head pressures or o.k.
ronnie helped me check them.
will check out the switch on the side of the block tonight.
but like i said before,unless my gauge is wrong,it doesn't get over 225 even sitting still with the A/C on.
i want it on with the A/C cause this 134 junk doesn't cool worth a #%*&!!!!
you can watch a temp gauge in the vent go from 40 to 65 after sitting for a few minutes.

where do i need to look for this other switch?? left or right side.
if it's bad,can i bypass it so the fan will stay on?

i beleive it is on the passenger head.its been awhile.......

i'll look this evening.
you gonna be around this weekend?

thanks

WOW !!! tore the grill off and checked everything,put back together.found temp sensor on drivers side head.disconnected,got a service engine soon light,put back on and cleared computer with the Hypertech programmer.
started her up and run in the driveway with the A/C on till it finally opened the thermostat.got to 195 and the fan came on!!!!!
it's MAGIC !!!! it hasn't worked since last year when me and Ronnie checked the freon pressures!!!!

must have had some corrosion in the connection. glad its working now! be safe on your trip.

sounds like some green corrosion built up in the connector are the temp sensor is going bad.

didn't see any corrosion anywhere,not to say it wasn't!
don't know about the sensor since i didn't get an engine light till i unplugged it.
hey, at least i learned how to get the grill off !!!!

note to self- get more small metric sockets !!!!

thanks guys