Scottsdale Upgrade Questions

[phantom110]

Hello all!
Just a few questions about parts and upgrades for an '85 C20 Scottsdale with the 350. My biggest question regards the HVAC system. My Scottsdale came with A/C which still works and blows cold and hasn't been retrofitted. My heater controls only have 3 settings: Defrost, Heater and A/C. I was wondering if it's possible to upgrade that control unit to the Delco #15-71268 that has the Economy settings and the different levels of A/C, like Normal, Hi and Bi-Level. ACDelco says it will fit in my vehicle, but doesn't say anything about compatability with upgrades.
Another question I have regards my dome light. This is minor, I realize, but the dome light doesn't work. The fuse and bulb are both fine. The light won't come on when either door is opened. Is this a bad ground or loose wire? Has anyone else had this problem? I can't seem to figure it out.
Also, does anyone else have problems with their intermitent wipers? Mine work perfectly on Lo, Hi and Mist, but won't work reliably on Intermitent. Any tips there?
Thanks in advance!

 

[73k5blazer]

Question 1)
Ok, I'm no expert in this area, but, if you already have AC, then you should have a vacuum controlled control unit. If that's the case, that's good, you have 1 'input' vacuum line and a whole bunch of output lines. The bi-level control just has more output lines and more vacuum servo motors placed in certain places on the ducts.
You'd need a diagram to see where you need those servo's and doors that they control, and I just packed away all my parts books because we're moving, I won't see them for a few weeks probably. Your best bet, however, is to go to a junk yard and pull all the pieces you need from a donor. All the ductwork, servos and the control unit. Then replace and repair as nesseasry when installing into your truck.
Questoin 2)
Dome lights are neagtive switch items in our trucks. So, 2 things to check, you should always have power (12v) present on one terminal at the light. So check for that with a test light or meter.
The door pins control the path to ground. What happens is they rust alot, just getting a wrench and turing the hex on the door pin is usally enought to restore the pin-to-body connection. You could also replace the door pin entierly, they rust internally too, the "Help" section at most any auto parts store carries those.
Question 3)
Your control box is bad. You need part number 15598496, $36 at gmpartsdirect.com. It's a little black box with aluminum fins tied to the base of the steering column. THis is what usally goes bad. It could also be the switch, part number 7844954. Get a real GM switch if you need to replace that, the aftermarket ones aren't as good. They have notches for the intermittent positions, the GM one has infinite adjustabity it it's intermittent section.
See also wiper tech post. The color are different, but it might help you in the long run.

Hope that helps!

 

[MuddinManny]

Question 1)

Question 3)
Your control box is bad. You need part number 15598496, $36 at gmpartsdirect.com. It's a little black box with aluminum fins tied to the base of the steering column. THis is what usally goes bad. It could also be the switch, part number 7844954. Get a real GM switch if you need to replace that, the aftermarket ones aren't as good. They have notches for the intermittent positions, the GM one has infinite adjustabity it it's intermittent section.
See also wiper tech post. The color are different, but it might help you in the long run.

Hope that helps!

You are the MAN! I needed those exact part numbers for my rig! Awesome! Thank you! I couldn't find them and was pullin' my hair out! You da MAN!

Wahooo! Intermittent wipers for me!

Manny

 

[MuddinManny]

2 items in cart
check out your
wish list order
status your
account SEARCH Advanced Search FAQ View Cart Register Request a Return Customer Service GM Warranty E-Mail Us Tell a Friend Home
Shopping Cart In most cases, gmpartsdirect.com total price (delivered to your business or home) is less than GM wholesale. Compare our prices with your local dealer.
GM
Part # Category Description Pack Qty Unit Price Quantity Ext.
Price YOU
SAVE Core Charge S&H Approx TOTAL Remove Part [SIZE=+1]*[/SIZE]7844954
All
SWITCH
1
$63.03
$63.03
$58.19
$0.00
$13.87
$76.90
[SIZE=+1]*[/SIZE]15598496
All
MODULE AM
1
$36.04
$36.04
$33.26
$0.00
$7.93
$43.97
Subtotal:
$120.87

[SIZE=+1]*[/SIZE] indicates special order item, which is a special order non-returnable part.

​

We currently only ship to U.S. postal street addresses. We do not ship to international addresses.
^ Back to Top ^ Performance Parts | Restoration Parts | GM Accessories | GM Merchandise | Specials | Vehicle Care | Wheels | Links
Advanced Search | FAQ | View Cart | Request a Return | Customer Service | GM Warranty | E-Mail Us | Tell a Friend | Site Map | Home ©2004 - Flow Chevrolet, LLC - All Rights Reserved. GMPartsDirect.com is independently owned and operated by Flow Chevrolet, LLC,
an authorized independent reseller of General Motors Parts. This site is not owned or operated by General Motors Corporation.
Privacy Statement | Site Policies | Warranty Disclaimer

Ouch! Prices are a little higher, but I'm goin' for it!

Manny

 

[GA84K5]

This is why it's great to be a member here. I've seen/bumped/almost disconnected that "little box with the huge heat-sink" a couple of times.
Now I know what it does and now I have a good indication of why my factory intermitant wipers don't work all the time as they should.

 

[obijuan]

mine have never worked intermittently. thanks. probably wont fix it till its real broke though

 

[phantom110]

Thank you very much for your help! I love being a member here because so many people are willing to lend their expertise; you're all great!