Hi all,

My heating system is not working right and the fan won't blow any air... winter is coming!

I've been working on this for a while with assistance from folks on alt.autos.volvo but I've reached an impasse. I have received some wiring diagrams and have made some assumptions that may be incorrect. Since this is a broader forum I'm hoping someone here can help me identify the cause of the problem so I can buy the right part(s). If you don't know the answer but can correct one of my assumptions that would still be great!

I have created a crappy website which includes diagrams and some info on what I've done and how I THINK the system works. Please have a look at http://home.eol.ca/~clubshub to see my testing results too.

Here goes...

1988 760 GLE with ECC (the 3-dial climate control: FANSPEED-VENTS-TEMP.)
-The AC system is KO'd (I removed the evaporator and dryer several months ago)
-Up until about a month ago heater worked fine, now the fan will not blow
-Overall the wiring is in very good shape, supple with no cracked connectors
-I pulled the fan and connected it directly to 12V and it works fine
-I have checked all related fuses (#10, #19, #28) and all are good
-I used a test light in several locations and got good results (see website)
-I have checked fault codes in the ECC and there are none
-Most recently I bypassed the relays (AKA. fan speed resistor, power stage, power unit, Volvo calls it a Control Module part#1365678) and still got nothing

At this stage I realise it'll be a part I need to buy I just want to know what part it is since several of them are $300+. I do have a voltmeter and have some readings there as well but nothing that explains to me why the fan won't turn. If needed I will post those results too.

Thanks in advance for your input!
blurp
--
1983 240 Turbo