blower not working on high

[Chrispbrown36]

I have searched the forum and everything I read said that typically if the high doesn't work it's the resistor. I changed the resistor and still nothing. The guy at the parts place told me to check the ground wire running from the relay to the grounding block and all looks good there too. The relay looks good too. What else should I look into?
Also, the connecting rod on top of the heater box was disconnected on my truck. I am fairly certain that I have it all back together as it should be, but does anyone have any pictures of how things should look on top of the heater box behind the glove box?
Thanks in advance.
Chris

[Bigstevex4]

I put a new Motor in for 20 bucks nothing else runs twice as fast those motors turn all time. they must have turned a billion times if never changed. Is it tiuning slow on high or not at all?

[rich weyand]

Year of your truck? A/C or not?

In the older non-AC trucks, the high is handled by a separate wire from the blower control to the resistor block. This is an ORN (orange) wire, and is connected at the resistor block into the same connector position as an BLK/ORN wire that goes to the blower motor. That is, this three-position connector has four wires into it. The one with two wires in it connects to both the blower motor and the control switch on the dash. So, sounds like bad connection on the ORN wire at one end or the other, or a broken ORN wire, or a bad fan switch in the dash.

[Chrispbrown36]

It's an 87 a/c truck. It blows normal in all but high and on high it isn't pushing any air out but does sound like something is moving in there.

[rich weyand]

I think the 87 is the same, except both wires are ORN (orange).

Could be that wire is rotting out or one of the contacts is bad enough it is not getting full voltage. You can check by pulling the connector, using a short piece of wire to jumper either of the other two connections into the connection with two wires, and then try the other two positions. One of them should now give you high blower. If so, as before, either one end or the other connection to the ORN wire is bad, or the ORN wire is bad internally, or the fan control on the dash is gefutzelt.

[Slammed84]

Check the grounds, I learned a interesting thing when putting my heater back together. Good ground to relay, and you must have a good ground to the metal housing of the blower motor. If not the fan turns at like half speed.

Its either that or your not getting full voltage at the resistor plug or relay. My factory wires were different colors than any of the schematics I found so I'll spare you wire colors.

Grab a test light and start prodding, you'll figure it out.

[Titomars]

Originally Posted by Slammed84

Check the grounds, I learned a interesting thing when putting my heater back together. Good ground to relay, and you must have a good ground to the metal housing of the blower motor. If not the fan turns at like half speed.

Its either that or your not getting full voltage at the resistor plug or relay. My factory wires were different colors than any of the schematics I found so I'll spare you wire colors.

Grab a test light and start prodding, you'll figure it out.

High works off of full battery voltage. So run a jumper from the bat + to the terminal on the blower motor this will check two things at the same time. If the motor blows spins up to full speed your motor and grounding is fine. if it does not then you need to try a jumper from bat - to the blower shell. If it gets to full speed now. This tells you if you have a ground issue. if it still does not go full speed the motor is toast and need replacing. this procedure bypasses all the factory wiring so you can rule out motor issues and or ground issues
Assuming the motor and grounding is fine the next most common cause of no high is a fried blower switch.

[Chrispbrown36]

I have kind of put that on hold since I do have everything but high. I am going to check the ground real well and try the jumper suggested by Titomars.
Thanks to everyone for the help.