: 70 CDV blower stuck on low



Jeff R
05-19-13, 10:11 PM
Hello,
New to the forum. Got a 70 Coupe DeVille a few days ago. The a/c is stuck on the low blower speed. It has the rotory climate control. The a/c does kick on so it appears the head knows where the selector is.

How can I troubleshoot this and/or how to I hotwire the blower on Hi??
Jeff

YoshiMan
05-20-13, 10:25 PM
if its running at a very slow speed, Then i think you are good to go. I'm not sure what year it started, but most of the 1970 Cadillacs run the fan constantly even if you shut the system off, just for ventilation purposes.

Jeff R
05-20-13, 10:43 PM
Yes, On low but I am not able to increase the speed so it gets quie warm in there. Is there anyway to hotwire the blower on hi?

CADforce69
05-21-13, 11:34 AM
Welcome to the forum, Jeff :)

Most probably your blower relay is bad. When it fails low speed circuit goes on through the ignition circuit but the rest of speeds do not run. Maybe you can find a new one on Ebay or get it repaired by an automotive electrician.

The relay is on the firewall, next to the transmission oil stick:

http://s13.postimg.org/l6pa24x5j/cadillac70green68.jpg (http://postimage.org/)


The blower relay is used to obtain a more direct feed, from the starter solenoid battery terminal, when the control lever is in "AUTO", "HI", "FOG", or "ICE". The relay coil feed is from the ignition switch, through the 25 amp switch where the circuit is continuous only in "AUTO", "HI", "FOG", or "ICE".

I had this problem on my '69. It had a non original relay but an electrician modified a modern relay to do the same function and substituted it so all speeds went ok since then. I hope your A/C works as well.

Jeff R
05-22-13, 10:39 PM
Thanks--- This is the information I have been looking for.
2 Questions.
First, How did you get it so clean under your hood???
Secondly, Is there a way to just hot-wire it for now and/or bypass the relay all together so I can get some air movement? Have only had the car a week, I don't even have plates on it yet but I need to take things a step at a time.
I guess 3 questions actually. What are some good troubleshooting websits, books,etc for this car?

Cady70
05-23-13, 12:49 PM
Take a few feet of wire and run it from the positive battery terminal to the blower motor. There's a single post conector on the blower that you can run power to. Then it's just a matter of popping the hood and unclipping it from the battery every time you stop.

CADforce69
05-23-13, 06:42 PM
Thanks--- This is the information I have been looking for.
2 Questions.
First, How did you get it so clean under your hood???
Secondly, Is there a way to just hot-wire it for now and/or bypass the relay all together so I can get some air movement? Have only had the car a week, I don't even have plates on it yet but I need to take things a step at a time.
I guess 3 questions actually. What are some good troubleshooting websits, books,etc for this car?

The car on that pic is not mine; its taken from a particularly well preserved (I would say in a time capsule) 70 CDV. Thats the original relay. The relay I found on mine was for an old Fiat - Seat or something like that. The one I have now is a modern one but it does its work. Anyway, cleaning the firewall is easy: Just an engine cleaner, a rag, a moistened cloth and some patience.

Im not particularly good at electric issues. The easiest solution is what Cady70 proposes (At least it will allow you testing if the blower motor works ok) but I will show you how the blower speed circuit and the relay works so you can find a better solution. I would take this diagram to a electricity shop so they can provide you with a similar relay and you can just unplug and plug to get your blower working as it should do. Maybe you can find this relay on Ebay. I bought one of these but I got a wrong one (maybe for an Eldorado).

http://s10.postimg.org/dsh6g2iy1/Blower1.jpg (http://postimage.org/)

http://s10.postimg.org/6b7z0utex/Blower2.jpg (http://postimage.org/)
share image (http://postimage.org/index.php?lang=spanish)

I strongly recommend you to buy a 1970 Cadillac Factory Service Manual (these pics are taken from the 69 FSM). Its an awesome help for all you need to know to repair and do maintenance works correctly. You can find some on Ebay.com:

http://www.ebay.com/itm/CADILLAC-1970-Shop-Body-Manual-CD-70-CD-ROM-/290463196167?pt=Motors_Manuals_Literature&hash=item43a0f4a407&vxp=mtr

http://www.ebay.com/itm/1970-Cadillac-Repair-Shop-Manual-70-Eldorado-Deville-Fleetwood-Calais-60-Special-/400314371866?pt=Motors_Manuals_Literature&hash=item5d34988f1a&vxp=mtr

http://www.ebay.com/itm/1970-Cadillac-Deville-Eldorado-Fleetwood-Shop-Service-Repair-Manual-CD-OEM-Guide-/140815091077?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1970|Make%3ACadillac&hash=item20c93bc585&vxp=mtr

http://www.ebay.com/itm/1970-Cadillac-Service-Shop-Repair-Manual-Book-Engine-Drivetrain-Electrical-OEM-/130741206009?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1970|Make%3ACadillac&hash=item1e70c87bf9&vxp=mtr

CADforce69
05-24-13, 07:24 AM
As to bypassing the connections, after watching the wiring diagram I would say that you should connect the orange and the Brown/White wires but youd better check it in the wiring diagram. Im no expert in electricity:

http://s24.postimg.org/lxsxhxch1/Wiring_Diag69.jpg
http://s24.postimg.org/l9p4w3k2t/Wiring_Diag69_1.jpg

This is a 1969 diagram. Im not sure how many changes suffered in 1970.

If Climate Control power servo does not work, maybe this by-pass or a new relay would not work. Forgot to tell you this could also be the problem.

Jeff R
05-25-13, 08:15 AM
Now this is what I am looking for. Thanks.
Yes, I plan to get a manual--Just haven't gotten that far yet. Have only had it a week.

CADforce69
05-26-13, 01:29 PM
When you have some time, you could post some pics. A lot of people in this forum would enjoy them for sure ;)

Jeff R
05-26-13, 09:25 PM
Will post some pictures as soon as I figure out how to.
Took the relay apart and cleaned it. It is working now. Working on the power servo now. Able to get it "hotwired" to get a stronger blower. Wedged something in the power servo to keep the rotating plate advanced to force the blower higher. It will work for now but will have to work on it when we need heat. Have to do this now because the front windows don't work.

CADforce69
05-27-13, 04:38 PM
Im glad to see you have the blower issue under control. You can buy a rebuilt power servo if you could not repair it: http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0&_nkw=69+cadillac+power+servo&_sacat=0&_from=R40.

As to the windows, they often stop working due to rusted connections at switches. Its easy checking it. You can hotwire the motors to see if thats the problem. Its easy getting other used or rebuilt ones.

You can upload an image by using the "image" icon (tree into a square) on the posting tool bar ;)