KOEO = Key On Engine Off.

OK good feedback on the jumper. SO, it sounds like the jumper is connecting to the 12 volt feed from the 40 amp fuse to the power relay, so that suggests that the wiring from the 40 amp fuse is ok, but the relay 12 volt feed to the solenoid isn't working, because you say only one of the 4 wires had 12 volts on it & you should have 2 with 12 volts on them at KOEO.

Apparently that's the 40 amp feed input To the relay, that's supposed to be switched by the power relays contacts & sent to the blower motor so it'll run.

SO, for some reason it seems the power relay solenoid winding isn't getting its 12 volt feed to operate & close its contacts when you go to KOEO???? Again, to confirm this, can you hear/feel the relay click at KOEO, so you know its operating????

If it isn't working, or not getting its 12 volts to work, you'll need to back up in the wiring to find out where its 12 volts is going missing. So begin by backing up to the in cabin instrument fuse panel for a 7.5 amp fuse in position 6 according to my manual, but check your owners manual for the correct position. If your lucky, the fuse is bad.

 

fuse was good and the 40 amp in the main power box separate from the heater fan relay box is being bypassed with jumper wire in place i can turn fan on pull the 40 amp and fan will stay on but i haven't tried to see what realy is doing as i cant on my own and weather hasn't been helping either

 

OK you say the in cabin 7.5 amp fuse is good, so I assume you just looked at it to see if it was blown, but at KOEO did you test its contacts to chassis ground with your 12 volt test lamp, or multimeter to see if it had 12 volts going to & through the fuse/on both sides of the fuse????

If it has 12 volts to & through the fuse, but the relay isn't clicking/working, then the problem is likely in the wiring between the fuse & the relay socket, or in the relay solenoid winding, as it could have a problem too. But right now, since you say you only have 12 volts on One relay socket/contact, it sounds like a wiring problem between the instrument panel 7.5 amp fuse & the power relay socket. Keep us posted on your trouble shoot.

 

Wooops, was just re-reading through the previous posts & just noticed that you said in post #12, that the relay "clicks", so its solenoid was working/clicking back then. So, if its still working when plugged in, but the fan motor doesn't run , suspect the power relay internal switched contacts, that close to send power from the 40 amp fuse to the blower motor, are corrupt. So try a new relay.

 

did that tried many different relays as i believe i said before i am gonna have to pull the box where the relay goes and look for broken wires that seems to be the only possibility at this point other than that i am not tearing into the wiring harness of the truck thats beyond my ability so if i can't figure it out soon i will just put it on a toggle switch

 

i tested all the other ports in the relay box with jumper wire removed and had power to only one spot in the box i have power at both sides of both the 40amp under hood and the fuse in fuse panel in truck i am pretty much lost at this point other than to remove box completely and check for broken wires

 

OK, if you have 12 volts B+ at the instrument panel fuse, but not at the power relay socket for the relay solenoid, then there is a problem with that wires continuity between the fuse panel & relay. As suggested before, maybe try a wiring harness wiggle, push, pull, flex test on the harness. Where it passes through the fire wall, or touches anything hot, or that vibrates, is suspect.

 

i have power at one contact in the box this relay is located in its own box separate from the main power dist box where the 40amp fuse for blower is with jumper it works on all speeds with out it i only have power at one terminal in the relay box and to access the harness that goes through the firewall i would have to remove the entire dash assembly and i am not doing that i have power to the main power dist box the harness seems to run from there to the other relay box i believe there is more than just the instrument pannel fuse like i said before i have power at one terminal only in the relay box that has the heater motor relay in it i feel like i am being talked in circles here i have limited knowledge on this stuff i am a diy person for financial reasons so for now untill i get to chasing some wiring it will remain as is and worst case i will put it on a toggle switch and be done with it

 

You have power from the 40 amp fuse to the relay, the problem seems to be that the relay solenoid doesn't have power to it, so that it can close the blower motor 40 amp feed contacts.
Think of the relay solenoid as an electrical switch that closes those contacts. It works electrically, like the toggle switch your talking about. The problem seems to be that the power wire that feeds the solenoid is open circuit.

I suppose you could rig a fused toggle switch to operate the solenoid. Don't think you'd want to rig the toggle switch to run the motor, as it draws Way more current that a toggle switch is rated for. Now the relay solenoid is another matter, as it draws Way less that the blower motor, as the relay solenoid is fused for only 7.5 amps & most switches can handle maybe twice that current load.

 

i can get a 25 amp up to 50 amp toggle at the parts store here in town i think there is an issue at the box that houses the relay i have tried many different relays to no avail so the relay itself i don't believe to be the issue there is something amiss in the area of that relay box i suspect but weather really hasn't been on my side latly i am going to check the junk yard when weather decides to be in favor of it to see if i can find another relay box and try replacing it and go from there other than checking my wiring job at the resistor and chasing the wires from that relay box i really don't know that there is much more i can do and sending it to a shop is simply not an option

 

OK, well I think you've narrowed it down to the 12 volt B+ for the power relay solenoid feed as being the problem, so if push came to shove, you could rig a switch to operate the solenoid feed, which would then have the power relay switch the blower motor high amp load as its designed to do. In other words the toggle switch would operate the relay from the cabin & the relay solenoid winding doesn't draw much current, its fused for only 7.5 amps, so it actually draws much less current & is easier to rig a switch circuit for, as it'll require smaller gauge wiring & switch. In any case you'd want to make sure to fuse that switch wiring, in case of an electrical short, so it won't catch fire.

Trying to control the blower motor electrical load, with a toggle switch in the cabin isn't a good safe way to do it. You'd need heavy gauge wire to handle the amp load, so it wouldn't get hot & catch fire, or have so much resistance that it would cause serious voltage drop to the blower motor & cause it to over heat!!!!

Yah I agree, keep looking around the relay box for the problem, as its exposed to weather & your in cold country with salted roads & thats hard on electrical connections, so if they're not protected, corrosion can cause all kinds of mischief!!!!
Keep us posted on your findings.

 

Another thought that I keep forgetting to post, when your checking the relay contacts for B+ to the relay solenoid, make sure the dash Heater/AC control ISN'T set to OFF or Vent, as those two positions turn B+ to the relay solenoid contact OFF!!!! So any setting except Off, or Vent, would apply 12 volts B+ to the relay solenoid to have it turn the blower motor on.

Of course it goes without saying that the in dash fuse panel 7.5 amp fuse for the relay solenoid must be good too.

 

yea mine doesn't have an off or vent only has def,floor,pannel and combo's of those other than a/c