While attempting to see if my '99 has heated mirrors (I think it does) I was activating my rear defroster and noting that it didn't seem to be doing much, if anything at all. I went to the passenger compartment fuse box and found a 10 amp fuse in slot 8 (rear defroster and heated mirrors) where there should be a 30 amp fuse. The fuse wasn't blown in so far as I can tell, and they're usually pretty obvious, but I put the proper 30 amp fuse in it's place. Would a 10 amp fuse be cause any weakness in the system? I can't think of any but seems wired that a 30 amp fuse would be spec'd when a 10 amp would "do the job." Any insight or thought would be welcome.

Oh, and I didn't get much of a chance to try out the defroster with the new 30 amp in it's place and I've already checked that the rear element is getting voltage and is a closed circuit and all that jazz.

 

you inserted the prescribed 30A fuse for F8 so you should be good to go.

 

That's what I'm hoping for! I just find it odd that (assuming everything is working right, heck of an assumption, I know) a 10 amp fuse would not blow on a circuit that calls for a 30 amp fuse. If fuse 8 powers the rear defroster, the 2 heated mirror elements along with the mirror motors maybe I could see it if they were planning for a worst case scenario like max current draw on the heating elements plus stalled motors for aiming the mirrors, plus a short all at once.

As a side note while working on this I did a detailed look at all of the fuses because and found two others that were the wrong current rating. Sometimes I really wonder about the history of my Disco, in so far as it seems that major repairs have been done but then all of the minor stuff (trim casings, connectors, etc.) had been put back together really shoddily. I can often times fix problems by just re-seating a loose connector. I guess I'll count myself lucky as far as that's concerned, honestly I think I "rescued" my rover from someone who maybe was not the best suited for 20 year old land rover ownership.

 

Reporting back that I was able to finally test it out on a cold morning with condensate on the rear screen and some on the mirrors. Things seem to work, I might have an open trace on the rear screen which isn't a big deal and it appears that my mirrors also worked, but I'm still skeptical as to weather it was due to heating or airflow as I was driving. At any rate it just occurred to me that I can use the thermocouple on my multi-meter to see if the temperature actually changes.