1987 Cadillac Brougham Blower fan works intermintently

BILL1015

MEMBER
1987 CADILLAC BROUGHAM
V8
2WD
AUTOMATIC
67,000 MILES

'87 Cadillac Brougham (RWD) has Electronic Climate Control unit in dash(ECC). Push auto button, no fan regardless of temp set. BUT, fan will just come on and work till vehicle shut down. The heat does work as you can feel it coming through vents. Same for AC Push defrost button, same problem. No fan but all of a sudden fan will come. Used to push defrost, fan would start and then push auto/ hi/lo and fan would work. No longer. It's just randomly going on/off. Put in replacement ECC unit. Did not solve problem. ECC seems to be working because it shows temp set, inside temp, outside temp and turns on rear defroster. Fuse okay. Proof seems to be the fan does come on/off but only when it feels like it.
Stumped. Thanks for any help

2 Replies

BUDDYCRAIGG

MECHANIC
2,262 POSTS

What about the fan amplifier?

And I don't remember the steps, so you'll have to get a book. But you can make the climate control do a self test.

Was this

answer

helpful?

Yes

No

Thursday, December 3rd, 2009 AT 12:27 AM

FACTORYJACK

MECHANIC
4,159 POSTS

It should just be a simple two wire connector at the fan. Best way to check it is with a test light, when the fan is not working, check across the connector. If the test light is lit, replace the fan. Try just rapping on the fan when it is not working. Often times dust, wear, and such causes the brushes in the motor to make poor contact.