TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > Body/Interior > HVAC
  New Posts New Posts RSS Feed - Blower Motor Relay
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

Blower Motor Relay

 Post Reply Post Reply Page  <123>
Author
Message
billd View Drop Down
Moderator Group
Moderator Group
Avatar
Forum Administrator

Joined: Jun/27/2007
Location: Iowa
Status: Offline
Points: 29690
Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Jan/14/2018 at 7:16pm
The style shown, 1970, often has an issue with oxidation and then downright rust. It's not the resistors inside that protective housing, it's the housing and terminals. 
Making them look good depends on how good the finish is today - elbow grease without giving it a high sheen may work but if the plating is gone due to exposure to the elements, it may take more.
I have taken them apart and replated the housing or shell and put them back together. 
Be careful cleaning the insulating plate the resistors and terminals are mounted in - you can't really get the original look back easily (at least in my experience)

In the one in the photo, I did replate the terminals themselves and the cover but did a high-sheen job on it for kicks. 
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 16213
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Jan/29/2018 at 7:56am
I put a standard relay on mine on the "high" speed (straight through, no resistor) in an effort to get a little more air moving. It didn't help much, maybe a little. At least I won't run any wiring hot! AC switch just trips the relay, which supplies direct battery voltage -- same as some do for headlights (I did that too, and was when I got the idea).  You can use a modern resistor pack, but will have to mod the housing and maybe the wiring connectors also. As stated, these are pretty robust, but if yours is missing/bad...  depends on if you have a restored car or driver, really. 
Frank Swygert
Back to Top
billd View Drop Down
Moderator Group
Moderator Group
Avatar
Forum Administrator

Joined: Jun/27/2007
Location: Iowa
Status: Offline
Points: 29690
Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Jan/29/2018 at 8:33am
I ha e Doug's apart. Terminals clean and plated. Housing in process. Biggest issue is keeping terminals clean to avoid heat and resistance.
Relays way to go on non-stock.
Back to Top
billd View Drop Down
Moderator Group
Moderator Group
Avatar
Forum Administrator

Joined: Jun/27/2007
Location: Iowa
Status: Offline
Points: 29690
Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2018 at 6:32pm









Back to Top
george w View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Jan/27/2013
Location: New Jersey
Status: Offline
Points: 1853
Post Options Post Options   Thanks (0) Thanks(0)   Quote george w Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2018 at 6:47pm
Night and day improvement in appearance. Some of these blocks had a distinct dark greenish tint to finish on the housing.

FWIW, AMC did offer a retro-fit A/C relay kit for the earlier pre-relay equipped models. The relay itself was/is mounted to the wiper plenum area above the blower motor. The kit includes the relay, which looks very much like a horn relay, a short wiring harness to tie into the existing blower harness wiring, two red power feed wires of different lengths for 6 and 8 cylinder cars that attaches to the battery side of the starter relay (solenoid)and a couple short hex head screws to attach the relay. There are at least three different part numbers for the same kit: 448 5922, 448 5936 and 812 1212

The relay provides for a 12 volt direct feed to the blower motor when the fan switch is placed in the high position. Takes the high current draw load off the fan switch and gets more voltage to the motor for a higher fan speed.

Edited by george w - Jan/30/2018 at 6:56pm
Long time AMC fan. Ambassador 343, AMX 390, Hornet 360, Spirit 304 and Javelin 390. All but javelin bought new.
Back to Top
DoughertyAMX View Drop Down
AMC Nut
AMC Nut
Avatar

Joined: Sep/20/2016
Location: Washington, Ind
Status: Offline
Points: 404
Post Options Post Options   Thanks (0) Thanks(0)   Quote DoughertyAMX Quote  Post ReplyReply Direct Link To This Post Posted: Jan/30/2018 at 7:00pm
Impressive!  Looks great Bill.
Back to Top
JeeperJolene View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Feb/11/2018
Location: The Big Globe
Status: Offline
Points: 66
Post Options Post Options   Thanks (0) Thanks(0)   Quote JeeperJolene Quote  Post ReplyReply Direct Link To This Post Posted: Sep/17/2018 at 11:37pm
The wiring in my 73 is shot and the blower switch is nasty looking. I'm looking to convert the switch so that it itself doesn't have any resistors in it, but instead controls relays that use resistor wires so that none of that draw is going inside the dash or through the switch. However, it seems I would need three relays to make that work:



There has to be a better way to do this or something else I could do that I'm not aware of. Any suggestions? As it stands now, I dare not touch that switch in its current state.
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 16213
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Sep/18/2018 at 5:35am
I can't see any other way. I just use one relay on mine (not a Javelin, 63 Classic), for high speed. You can use miniature relays instead of the typical automotive relays. I had to replace a circuit board in a kitchen range a few years ago and was surprised to find miniature relays on the 220V controls. You would need a small piece of breadboard to mount them, but weouldn't take up much room.
Frank Swygert
Back to Top
JeeperJolene View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Feb/11/2018
Location: The Big Globe
Status: Offline
Points: 66
Post Options Post Options   Thanks (0) Thanks(0)   Quote JeeperJolene Quote  Post ReplyReply Direct Link To This Post Posted: Sep/20/2018 at 1:37am
Breadboard is actually a pretty good idea. If I go that route then I'll post the parts list and schematic that I make.

I guess all that's left is figuring out what kind of resistance I need for low and medium. I did some Google-fu and wasn't finding what I need. Since the switch is shot, I can't really read the resistance on it.
Back to Top
304-dude View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Sep/29/2008
Location: Central Illinoi
Status: Online
Points: 7558
Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Sep/20/2018 at 5:30am
Ha a bread board. Why not simplify things if rewiring without the factory resistor block.

A simple pulse width modulation will do the trick. It controls how often or I should say steady current is sent to the motor. Many motor drives are pulse width modulated, as the circuit runs cooler and is more accurate in speeds.

There are many kits or modules to wire up in series. Some are very simple 555 timer, capacitor, potentiometer adjusted, with a driver transistor. Others are built with a PLL circuit and binary circuit for forward/reverse and preset multiple stage motor control.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=pulse+width+motor+control&_sacat=0
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
Back to Top
 Post Reply Post Reply Page  <123>
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.172 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or