bomar76

1987 Coupe with C68 Electronic Climate Control
Blower stopped working both Automatically or Manually

Back ground info:
When son bought Vette C68 ECC was wonky and began a nasty habit of only going UP from default setting of 75 on temperature selection, would not go down regadless of what buttons pushed. Disconnecting battery would reset temperature to 75, pulling fuses would not. Sent Control Head off to be repaired over a winter, when returned same issue. Repair shop no help. We learned to live with it.

A week ago the blower ceased functioning.
Fuses good, blower will run if jumpered so motor good.
Pulled 2 wire and 4 wire connector on blower motor resistor module and jumpered across red wire and on two wire plug and black wire on 4 pole plug. Blower runs.

Exisiting blower resistor assembly is Delco 16061602
Rock Auto shows this superceeded to Delco 1572530

Pretty sure it's the blower motor resistor module, so will order one.
Scoured the breakers yard this AM for one from an appropriate mid 80's-early 90's full size BOP or Caddy with the ECC but all they had were the 2 plug 4 total wire modules. Was one car that once had one, someone beat me to it.

Finally got the Climate Control Head to go into Diagnostic mode.
Had to use what I believe to be the 1989 method:
1. Press and hold Ext Temp
2. Press Auto Fan
3. Release Auto Fan
4. Release Ext Temp.

That method will get unit to display the 9 Modes
I get these readouts:
Mode 1 - Program Number 53 , 55
Mode 2 - In Car Thermisitor 102
Mode 3 - Ambient Correction 73
Mode 4 - Blower Number 5
Mode 5 - Outside Temp Thermisitor 77
Mode 6 - Feedback Pot Position 154
Mode 7 - Calculated Door Position 155
Mode 8 - System Faults 00
Mode 9 - Software Version Number 82

I do not get a flashing EXT TEMP annuciator that would indicate a system fault, and since Mode 8 indicates none, I would assume that is good.
FSM says to refer to section 8A for further diagnosis, there is no section 8A in the 1987 FSM.
Anyone know if the above codes mean anything out out of whack?

SunCr

There's no faults; numbers are pretty much meaningless for your Year.

Make sure the Blower Connector wiring isn't discolored around the Connector. If so, it's dropping volts and the terminals need to be soldered to the wires.

I'm guessing you need a new Panel because your symptoms - if at 75 everytime you start it - means it's losing Memory. Check ground which runs to the Driver's side Kick Panel. It's on it's own lug and is bolted up with the front harness ground at this location.

You do need a new Blower Module too. Guess our cars have gotten so old that it's hard to find a good used one though a ton of these were on Caddys. '90 is when they switched over to the single harness (eliminated compressor ground which was switched to the ECM) so anything before that should work.

bomar76

Thanks man. Appreciate the guidance.
The temp up/down issue seems to have healed itself, and if not we can live with the 75 issue.
No discolored wiring (resistant) issues anywhere in that harness. I'll check the ground tonight.
I'll hit a couple more breakers and maybe find a blower module. If not, Rock Auto has them for $125 or so new, minus the always present 5%.

Keystring

I had this same issue on my 87.

The control unit would 'flake out' when ever it had a mind to do it.

I took the unit out and removed the cover. Once the cover was off I discovered the unit was two piece, the back half plugging into the front through a connector.

I separated them and cleaned the connectors on both halves. Put it back in and it worked fine all winter.
Just recently it started doing it again, so I probably didn't clean it as well as I should have. I plan on doing it again soon.

The BCM was another thing. I would park the car overnight and then next morning my battery would be dead. Hooked up the charger and the Blower fan and inside lights would come on right away. Even with the key off!!

I disconnected the battery and put the charger on for a few hours and everything would be fine, until the next day.

I originally thought the BCM was bad and draining the battery, but I was wrong.

Turns out the battery was 'iffy' and once the voltage dropped below 10 volts, the Blower fan would kick on and kill the battery the rest of the way. The BCM is directly connected to the battery so it's always 'hot' even with the key off!

Replaced the battery and everything has been fine ever since.

I did buy a used BCM off of Ebay for $12 and it worked fine, so I'm just keeping it as a spare.

1986coupe

I just did mine on my 1986 about a month ago. You will need to replace the module under the hood. If that doesn't solve it then you need to replace the actual control in the car...that is the expensive part.

bomar76

UPDATE~ RESOLUTION:
Finally made another trip to a breakers yard today. Searched the BOP/Caddy Land Yachts of appropriate vintage, all had the harness with 1 wire/3 wires.
Decided to pull one to try, it had a different PN and looked very different, a big assed transistor hanging out one side. Thought what the Hell, might as well try one.
Decided to pull a second one as a spare just in case (still 1 wire/3 wire harness) and low and behold the module was a Delco 16061602 exactky like the Vette.....searched a few more 1 wire/3 wire and some of the were 16061602 and others were the different unit (sorry, no pn for those).
It appears the 16061606 modules were used in a lot of BOP/Caddy Land Yachts with the different harness than the Vette, so if you are searching junkyards for used units be sure to check every one.
The cost per unit used was insanely cheap.
We installed a used take out from breakers yard and low and behold everything works perfectly now.
Blower works on all 10 levels and the Temp Up/Down buttons work as they should.
I belive all our old problems with the Temp Up/Down on the Climate Control was the Blower Control Module having issues, and when the module finally gave up the ghost for good it stopped screwing up the head unit.

So....in review:
Just because the harness is different on some vehicles it may be the same module, you have to remove and look.
A new blower control module fixed the blower issue.
I believe all the old issues with head unit were really caused by a bad blower control module.

aviography

Folks,

Stumbled across this thread while trying to figure out if the BCM p/n 16061602 was the culprit for my father's 1990 Olds Delta 88 with the fan stuck on even without the key in the ignition. Right now I've got it rigged with a relay triggered by the radio-on voltage to connect the power to the fan so the blower can coninue to work without my father worrying about a dead battery.

I will post a WTB in the Classified Section as I haven't found a similar vintage car in the salvage yard around the area, in the mean time would anyone have an extra one of these and is willing to sell/ship to Toronto area to me? Will pay in advance to ease any concern.

SunCr

Check 5 amp fuse protecting the return signal. I have no idea where it is on an Olds. There should be a splice off of the Blower hot wire - purple or red/black - that runs to this fuse. If it opens, it defaults to High Blower and may run with the ignition off.