engine fan relay

#1
I have a 1998 peterbilt 379 3406e cat. The three relays inside the dash, on the one relay for the fan number 85 is the ground, and that wire is a 239, the 86 on the relay and that wire is the 522 is called fan disable, and the 87 is the fuse 10 amp and thats number 220 wire, and the 30 is ignition power fuse thats a 226 wire. My question is, with the key on am I suppose to get power to the 522? I get power from the 220, but I don't get power from the 226 or the 522. Driving down the road the fan won't come on when it gets to 215 temp the buzer comes on and the warning light, I override it and the fan comes on and lowers the temp. My fan will come on and off with the a/c idleing, but not going down the road with the a/c on. I replaced all the sensors, the relay valve on the firewall all the fuses and relays are good (that I found). In the fuse box there is all fuses in there but #1 spare. For some reason if I put #1 in the fan will come on but not go off, and the four fuses in the dash the #3 fuse in the dash, I checked that fuse when I put the #1 fuse in and there is power to both leads and if I pull the number 1 back out I get no power unless I override the switch. I also checked all the wiring from the motor to the firewall, and found no broken wire.

I appreciate any and all help.

Thanks
 
#2
I made a mistake. The fuses inside the dash I do not get power to at all until I turn on the manual override switch, then I have power. Should i have power to these relays?

Thanks
 
#3
Hi I would think u should have power to the relays. On my pete its a 99 with a 6nz my relays have power then it runs up to the over ride switch.
 

JMC

New Member
#9
I have a similar problem with a 379 peterbuilt has a C15 engine which is not origional. Problem im having im in australia and i can't get hold of any complete wiring schematics.
 
#10
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