Dash fan doesn't work

[cosmic]

OK so my dash fan will not go on. I read what I can on here. I find the solenoid under the high beam board on my 75 brave d21.
I take a screw driver and jump the solenoid. fan turns on but only in high. figure its a pooched solenoid even though I here it clicking on when i turn the ignition switch to the on position.
Order a new solenoid (constant voltage) or (continuous) not a starter solenoid. I install it and have the exact same problem. the fan only turns on when I jump the solenoid with a screw driver.
Is the new solenoid broken. Not likely but could be. Any ideas anyone. I'm at a stand still here. the solenoid is ground to the steel floor. What else could I possibly check?
i?? i??

[DaveVA78Chieftain]

12VDC battery power should be at one of the 2 large posts (most likely the one nearest the sidewall).  Confirm voltage to at least one large post.  If so, jumper from that large post to the small post.  Does the relay energize?  If no, relay is bad.  If yes, relay control from ignition switch is missing.  Sorry, I do not know exactly where that comes from.  Most likely fed from one of the chassis fuses attached to the steering column (HEATER or BAT ACC).

Dave

[cosmic]

the fan side is the right side (big one) I think i read some where that the left side big one is for the aux. fuel gauge.
I have not jumped the left side because when i jump the right side Big right to small center the fan kicks on. I do here the click of the solenoid when i turn the ignition switch to the on position... but the fan does not work... jump it and it and the fan works.
If I new it would not catch fire I would run a thick gauge wire to both and jump it permanently, problem solved. just don't want a pile of ashes in the morning....

[DaveVA78Chieftain]

The click sound you hear has to be another relay or the thing would be working.  If you can jumper from the big post to the small post and it works.  That is telling you the signal to the small post is missing when you turn the ignition switch on.  Additionally, the big post you jumper from would be the "hot" side.  The other side would be going to the fan circuit.  Relay (solinoid) does not care which side the "hot" is on.  The fans Winnebago used apparently draw higher amps than a normal auto fan therfore they installed the solinoid to manage the higher current draw.  Dodge Heater fuse is only 20 amps.

Dave

[cosmic]

no the click is definitely the solenoid. I put my finger on it as I turned the key. same as the old one. I just went back out side and ran a jumper to the frame from the case of the solenoid to be certain it is grounded. Same thing. solenoid clicks 100% but no fan until it is jumped.
What are the odds that 2 solenoids click when the key is turned on but don't get the power through them. One is brand new.
now keep in mind as i said in the beginning the fan only works on high not the other 2 settings but That is how it always worked. I think the switch needs to be taken apart and contacts cleaned. That's another issue to deal with later.

[jkilbert]

Also check the blower motor resistor. When these fail they default to the high setting for safety. it is usually located near the blower motor.


john

[cosmic]

any other thoughts. this has got me completely bewildered. i??