PINPOINT TEST G: THE BLOWER MOTOR IS INOPERATIVE
Test Step Result / Action to Take
G1 CHECK BLOWER MOTOR GROUND
• Disconnect: Blower Motor C1227 .
• Turn the blower motor switch to the HIGH position.
• Measure the resistance between A/C blower motor C1227-1,
circuit 261 (OG/BK) and ground.
• Is the resistance less than 5 ohms?
Yes
GO to G4.
No
GO to G2.
G2 CHECK CIRCUIT 261 (OG/BK) FOR AN OPEN
• Disconnect: Blower Motor Switch C294b .
• Measure the resistance between blower motor switch
C294b-1, circuit 261 (OG/BK) and blower motor C1227-1,
circuit 261 (OG/BK).
• Is the resistance less than 5 ohms?
Yes
GO to G3.
No
REPAIR circuit 261 (OG/BK) for an open. TEST
the system for normal operation.
DIAGNOSIS AND TESTING(Continued)
2005 E-Series, 10/2004
PINPOINT TEST G: THE BLOWER MOTOR IS INOPERATIVE (Continued)
G3 CHECK CIRCUIT 57 (BK) FOR AN OPEN
• Measure the resistance between blower motor switch
C294b-2, circuit 57 (BK) and ground.
• Is the resistance less than 5 ohms?
Yes
INSTALL a new blower motor switch.
No
REPAIR circuit 57 (BK) for an open. TEST the
system for normal operation.
G4 CHECK A/C BLOWER MOTOR CIRCUIT 515 (OG/RD) FOR VOLTAGE
• Ignition ON.
• Measure the voltage between A/C blower motor C1227-2,
circuit 515 (OG/RD) and ground.
• Is the voltage greater than 10 volts?
Yes
INSTALL a new blower motor.
No
GO to G5.
G5 CHECK CIRCUIT 515 (OG/RD) FOR AN OPEN
• Ignition OFF.
• Disconnect: Blower Motor Relay .
• Measure the resistance between blower motor relay
connector pin 87, circuit 515 (OG/RD) and blower motor
C1227-2, circuit 515 (OG/RD).
Yes
GO to G6.
No
REPAIR circuit 515 (OG/RD) for an open. TEST
the system for normal operation.
DIAGNOSIS AND TESTING(Continued)
2005 E-Series, 10/2004
PINPOINT TEST G: THE BLOWER MOTOR IS INOPERATIVE (Continued)
G5 CHECK CIRCUIT 515 (OG/RD) FOR AN OPEN (Continued)
• Is the resistance less than 5 ohms?
G6 CHECK THE BLOWER MOTOR RELAY
• Connect: Blower Motor C1227 .
• Ignition ON.
• Connect a fused jumper lead between the blower motor relay
socket pin 30, circuit 364 (BK/LG) and pin 87, circuit 515 (OG/
RD).
• Does the blower motor operate?
Yes
GO to G7.
No
VERIFY the battery junction box (BJB) fuse 17
(50A) is OK. If OK, REPAIR circuit 364 (BK/LG)
for an open. TEST the system for normal
operation.
G7 CHECK CIRCUIT 57 (BK) FOR AN OPEN
• Ignition OFF.
• Measure the resistance between blower motor relay socket
pin 86, circuit 57 (BK) and ground.
Yes
GO to G8.
No
REPAIR circuit 57 (BK) for an open. TEST the
system for normal operation.
DIAGNOSIS AND TESTING(Continued)
2005 E-Series, 10/2004
PINPOINT TEST G: THE BLOWER MOTOR IS INOPERATIVE (Continued)
G7 CHECK CIRCUIT 57 (BK) FOR AN OPEN (Continued)
• Is the resistance less than 5 ohms?
G8 CHECK THE BLOWER MOTOR RELAY
• Ignition ON.
• Measure the voltage between blower motor relay socket pin
85, circuit 753 (YE/RD) and socket pin 86, circuit 57 (BK).
• Is the voltage greater than 10 volts?
Yes
INSTALL a new blower motor relay. TEST the
system for normal operation.
No
GO to G9.
G9 CHECK CIRCUIT 753 (YE/RD) FOR AN OPEN
• Ignition OFF.
• Measure the resistance between blower motor relay
connector pin 85, circuit 753 (YE/RD) and function selector
switch C294a-3, circuit 753 (YE/RD).
Yes
GO to G10.
No
REPAIR circuit 753 (YE/RD) for an open. TEST
the system for normal operation.
DIAGNOSIS AND TESTING(Continued)
2005 E-Series, 10/2004
PINPOINT TEST G: THE BLOWER MOTOR IS INOPERATIVE (Continued)
G9 CHECK CIRCUIT 753 (YE/RD) FOR AN OPEN (Continued)
• Is the resistance less than 5 ohms?
G10 CHECK CIRCUIT 489 (PK/BK) FOR VOLTAGE
• Ignition ON.
• Measure the voltage between blower motor switch C294a-4,
circuit 489 (PK/BK) and ground.
• Is the voltage greater than 10 volts?
Yes
INSTALL a new function selector switch.
No
VERIFY the central junction box (CJB) fuse 13
(15A) is OK. REPAIR circuit 489 (PK/BK) for an
open. TEST the system for normal operation.

Hopefully that is clear enough to understand, it may seem long but its quite an easy test. Hopefully this helps, let us know.

 

all the parts i replaced were blower motor, blower control switch, relay, resistor, resistor conector pigtail. all parts are from autozone not oem parts. i will have to buy or borrow a ohm meter and try to follow this pinpoint test. but seams over my knowledge.

 

Yea an ohm/volt meter would be helpful. You replaced most of the parts so you should already know where all the connectors are. like i said it seems like a lot but take it slow and you'll get to the bottom of it. no lift required just under the hood a little bit and at the passenger side of the vehicle. Not to bad if you need anything else just post here. Instead of guessing parts this test will find the culprit.

 

i will print this out and try to go through it. thank you.

 

Ok, I'll jump in too

So,, you 'had' high fan function, and now none...

Lets start there..

The blower motor relay gets its 'switched' power distribution through the control panels Mode Switch not the panel Fan Function Switch. Being you don't have a complaint for modes not working (floor, defrost, A/C etc) shouldn't be a concern here or fuse issue..

The fan function speed control is really nothing more than a selectable/circuit ground for the blower resistors seperate/resistances to control fan speed. The blower motors 'load' or power distribution comes from the BJB (battery junction box) fuse #17 50amp and on out and through a closed blower relay. Since you added a battery power source to the blower connector (?), double check the fuse or even the harness around the box. Being a retired service wagon, I've seen all kinds of issues with emergency and commercial rigs after all the equipment was yanked.. Fuse/box tap problems when removed, splice problems, cut/exposed wires, loose grounds etc..

Try as a quick check with a test light,, remove the blower motor relay,, you should have 12v 'Hot at all times' on 'one' leg of the relay connector with the Key Off,, then cycle the key to On/Start,,, you should now have 12v on '2' legs of the connector.. Don't worry about the others...

If not.. stop.. Which one?

Next,, if you do have 2 legs 'hot' at the relay connector ('Key On'), replace the relay and go to the blower motor connector.. If the new relay is now installed and closed/active,, then there 'should' be 12v on the OG/RD wire at the blower motor connector.. Seems that statement would be no ,, since your adding voltage there.. If no,, may need to back track..

If yes,, and no fan,, you should be able to use a test lead and back probe/ground the OG/BK wire and should have 'high fan'..

If that works,, go out to the blower resistor,, back probe the LB/OG wire there with a test ground lead. Med/High fan should come on,,, next if you want,, ground the RD/OG and Med/Low should come on.

If you have 12v at those test points, and the grounding tests control speed/s, then the problem should be in the fan function switch or its connector.. Doubt the new switch is bad though, ..but... Since you changed out the blower motor, make sure the ground for the resistor is still tight.. If none of these test work,, or stop you at any point, post the results..

 

im going to look for a wire diagram image too. that would help me understand where all the wires go. thanks everyone i will post when it's sorted out.

 

If your using a test/continuity light (?) and checking at the blower motor connector for voltage there and have none?,, the easiest way to check the related fuses for an open (and as a first step for power distribution) is to just pull the blower relay and check there.

If power is there on 2 legs (Key On/Start position), then you can work towards the blower motor.. If not on both legs,, then given 'which one' (if any) are dead directs the search, as well as proves out others. Could be a voltage drop/ground too, but most times not.

The blower relay connector is the 'Golden Egg' in that power that closes the relay (and ground) as well as the power to supply the fan motor are there. One with the key off, 2 with it on. Simple..

If 'either' is missing,, chasing wire may just be extra work. I could find you some info, but the system is really pretty simple and a few basic checks would help in a direction. There's always the 'odd ball' that can through off a diagnosis, some problems that someone generated, others not..

If you've run a temp POS wire from the battery to the OG/RD wire at the blower motor and 'ALL' the blower speeds then work (?), then it's not in the control panel, at least on the fan selector switch/connector side.

If you've added a ground at the blower motor and only have high fan, then it could be. Believe you only added a hot wire,, correct?

 

i ran 2 wires conecting the blower motor and battery then ran them inside the van so when i need heat i conected the wires and it was only high speed. i'm going to check everything in the morning. ill post my progress. thanks all

 

i think my problem is G9 on the pin point test. circuit 753 going to check it out later

 

yep. must have wore a spot on the wire. i ran a new one and it works fine now. thank you everyone for the help. i have heat again. LOL!