97 Disco with a ton of electrical issues due to leaking sunroofs that I fixed when first bought.

The blower motor was working fine then one day stopped. I was able to pull the relay and add a jump wire to get it to turn on. That worked for awhile but recently stopped. I've checked all fuses, fusible links in the engine, checked the blow motor resistor thing which looks good, swapped the multifunction unit, swapped the whole fuse box which fixed some light issues but nothing has worked for the blower fan. Tried a used one from parts truck but it didn't work. Have another known working one on the way to try but not convinced its the issue. I also took out the switch on the HVAC panel to clean which didn't do anything and also looked in good shape. May try a used one.

Where are the grounds that control the blower? Any other thoughts?

 

The electrical troubleshooting manual (ETC) for your and many others can be found in the Google drive linked in my signature. Go to the Discovery 1 section and download the document etlj970x - electrical.pdf .

Section "K1" deals with the blowers and the controls (page 238 in that copy of the manual)

Help yourself to whatever other documentation is in that drive.

 

Keep in mind the fan control works on the ground side of the fan using the fan resistor pack to limit what is grounded . Not like the U.S. which limits the power side of the fan and runs the other side of the fan straight to ground. Documented in etlj970x - electrical.pdf Kind of confusing if you are used to USA prints. took me a bit to get used to it.

 

Thanks for sharing the links. I actually had the electrical manual but forgot all about it!

Looks like there are two relays, K127 gets energized first, then energizes K192. K127 appears to be behind the kick panel and K192 is by the blower itself. These power the blower motor and ground is applied though the resistor unit.

Between the 2 relays, the resistor, fan control and motor itself one of these has to be the culprit. Just hoping its not something random like the fuse box that fixed a bunch of other things.

 

where did you get those pictures from ?

 

Looks like they are cut/paste from the electrical troubleshooting manual in the "Component Location Views" section.

 

Yup exactly. They are from the etlj970x manual. You can ctrl+F the connector name and find the photo which helps a ton to locate in the truck.

So it was the K192 relay. I swapped it from a parts truck and the fan started working. The resistor immediately popped though which only allows full blast to work. Im waiting to try out a late 90s Dodge ram resistor which looks the same and way cheaper.