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Blower Motor Resistor

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10-15-2020, 10:53 PM
Jim and Tere
Blower Motor Resistor
In trying to determine why the blower motor will not work, Tere has narrowed it down to the blower motor resistor. The odd thing is that it is attached to a plate sitting on top of the radiator. What I've read is that it should be on the other side of the fire wall, close to the blower itself and actually in one of the ducts. I'll attach a picture but I don't know if I resized it correctly. The question is where should the resistor be located?
thanks
Jim




Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
10-16-2020, 07:05 AM
Danny Z
I just replaced one in my Ranger. It was located on the blower motor housing under the hood in a very inconvenient and hard to get to place. Perhaps GM borrowed this "better idea" from Ford and a PO decided to make it easier by fabbing up what you show in the pic. The plug is identical so I'm sure that you are looking at the right thing. You didn't say what the symptoms were, but it usually is no fan on 1, 2, and 3, then full blast on high.
BTW, I'm going to fetch the wiper motors from my warehouse today to see if they are what you need. I'll let you know.


79 Barth Classic
10-16-2020, 09:21 AM
Jim and Tere
Thanks, Danny. At first, we had no power to the motor at all. After some wiring cleanup, Tere was getting intermittent power to the motor which is under the dash on the passengers side. On the engine compartment side of the blower is a big box and I really don't know it's function. I guess it is the heater box. Probably originally contained the evaporator. Looks like almost impossible to get to.

Jim


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
10-18-2020, 11:42 PM
Jim and Tere
Still haven't figured out where the blower motor resistor should be located. Perhaps someone with an 88 or 89 could tell me where theirs is. Ours was mounted on top of the radiator and exposed to all the elements, i.e., water etc. Most of the people I talk to say that blower motor resistors are usually mounted either in the air flow of the blower or on the side of the blower housing. I could do that but others say the resistors get hot and need air to keep them cool. We've ordered a new resistor which should be here this week.
Jim (aka Hum)


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
10-27-2020, 09:29 PM
Jim and Tere
We replaced the resistor with an exact duplicate, part # and everything, and now the 3 low speeds work. The resistor has 5 blades however the plug going to it only has 4 slots. Tere found a hot wire in the engine compartment that was not connected to anything and she attached it to the 5th blade on the resistor and now the 4th speed on the blower works. So, I should be satisfied, right? Two things:
1. The resistor gets hot as heck when the blower motor is working. So hot, you can't even touch it.
2. All the GM drawings I have and I have good ones, show the blower motor resistor for both the 1988 RV chassis and the 1988 P chassis, both forward control, and motor home, show the blower motor resistor in the housing where the blower motor is and it is accessible from the inside of the rv. None of the drawings show the resistor in the engine compartment. It just seems to me that a resistor that gets so hot it has to be put in the engine compartment where air can get to it, is the wrong resistor. Of course that's the logic of a guy who can't even be considered a shade tree mechanic.

Jim (aka Hum)


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
10-28-2020, 06:52 AM
Doorman
Normally the resister is in the blower housing where air from the blower blows the heat away. If it works where it is at i would call it fixed. Go take an overnight trip and enjoy it. Don't need AC this time of the year so you don't need the gen. By the way . Congrats on your new coach. I always liked the FP in that coach. Stay safe


1986 31' Regal -1976 Class C
454/T400 P30 -350/T400 G30
twin cntr beds - 21' rear bath
10-29-2020, 09:06 AM
Jim and Tere
If there is anyone out there that has an 89 Regal either a 25'er or a 28'er, I would appreciate it if you could tell me if you have a resister in the blower motor housing. The blower motor is on the passenger side, easily seen by just looking under the dash.
Thanks
Jim (aka Hum)


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
11-04-2020, 05:56 AM
Steve VW
My 86 Regal had the resistor mounted on top of the radiator. Worked fine.


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
11-06-2020, 02:26 PM
Jim and Tere
Well, that's where mine is. Isn't that special??


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
06-14-2021, 09:54 PM
2Puppers
Jim and Tere, where did you find that random hot wire? I'm in the process of cleaning up all the wiring and electrics behind the grill of our 88 Regal. I found my blower resistor plugged in but just stuffed up into some wiring. Nothing is attached to the lone 5th blade.
06-20-2021, 06:14 PM
Jim and Tere
Just saw this. Mine has stopped working again. the 5th spade wasn't used on mine. Or it had something to do with the dash a/c. This was removed when Doris & Marvin owned several years ago. I'll send Amy a pic.
Tere


Jim and TereJim and Tere

1985 Regal
29' Chevy 454 P32
8411 3172 29FP3B
Gear Vendor 6 Speed Tranny
06-21-2021, 10:29 AM
BarthBluesmobile
quote:
Originally posted by Jim and Tere:
Perhaps someone with an 88 or 89 could tell me where theirs is.
Jim (aka Hum)


I tend to think that P37 vehicles with the 454 didn't change much from year to year in the 1985.5 through 1990 timeframe, in terms of the basic design.

On mine, the component is "hanging loose" next to the windshield washer tank. Clearly the reattachment to the intended position was an oversight by a mechanic at some earlier point.

I'll add that to my "pre-flight checklist"...
Matt


1987 Barth 27' P32 Chassis
Former State Police Command Post
Chevrolet 454
Weiand Manifold, Crane Cam, Gibson Exhaust
06-21-2021, 12:49 PM
Doorman
Just looked at my coach and found my resistor box mounted on the corner of the a/c condenser. I think the fact a/c -heater are mopar controls and not GM. they might be wired different. I bet this left for the coach builder(Barth) to instal. As long it working I think I will leave it be.


1986 31' Regal -1976 Class C
454/T400 P30 -350/T400 G30
twin cntr beds - 21' rear bath
06-21-2021, 01:30 PM
Steve VW
As for fan motor function, my 86 would only blow air when a vent function was selected. If the vent selector was in the off position, the blower did not come on at all regardless of the blower speed setting. If any vent funtion was selected the blower ran constantly at one of the four speeds.


9708-M0037-37MM-01
"98" Monarch 37
Spartan MM, 6 spd Allison
Cummins 8.3 325+ hp
10-09-2021, 12:17 PM
BarthBluesmobile
Part of being a prudent Barth owner, is knowing when to "pay" and when to find an alternative. Because of my focus in the last year on what has turned out to be the beginnings of a restoration, I found websites to assist in finding alternatives.

The stock blower motor resistor in our late 1980s Barth rigs (Regals at least) is the Ford D32H-19A706-AB. Some sellers on ebay want over $100. There are RV parts dealers which want over $50.

I've browsed the Dorman website (yeah get a life buddy) and found that a "near hit" is the Dorman 984-604. That part with new pigtails for the 4 conductor connector and the 1 conductor connector lists as 973-478.

The Dorman 984-604 cross references to the Ford E8UZ-19A706-A. There are few differences to note:
- there is what I think is a zener diode in series with the heavy gauge (low resistance) wire, I assume it is there for transient suppression and has an appropriate voltage rating (if it worries you, add in a bypass wire)
- the "solo" connector tab is offset (but that is of no consequence)
- the mounting holes are not aligned with the 4 conductor connector (so you will need to rotate the circuit board 180 degrees, or drill new holes in the circuit board to mount to the stock bracket depending upon the clearances of the conductive paths to your bracket)

The intended application of the Ford E8UZ-19A706-A is the 1988-2002 Econoline van family.

Happy Barthing!
Matt

blower motor resistor



1987 Barth 27' P32 Chassis
Former State Police Command Post
Chevrolet 454
Weiand Manifold, Crane Cam, Gibson Exhaust