Aug 232011
 

The Chilton’s manual for the range of trucks that includes mine includes a wiring diagram that is supposed to be year specific. This diagram shows a fuse panel marked ‘Horn’ under the relevant slot, when the stock fuse panel is, in fact, marked ‘Horn/DM’.  What does the ‘DM’ refer to, and more importantly, what all is served by this fuse??

I’m chasing a short that has this fuse apparently directly affecting the operation of both my fuel pump and my dome lights that I’m aware of at this point. This short is probably the direct result of wire overheating due to a much nastier short in the rear loom that I just repaired.

  3 Responses to “89 GMC Jimmy”

  1. Is this the 2.8L engine or 4.3L engine?

  2. 4.3L auto 4×4 air & pwr lcks n wdws. Have since discovered that apparently the dome lights are supposed to go thru that fuse, tho I still don’t know if the fuel pump should. Have identified the fuel pump relay, and, correct me if wrong, but should have 12v or something at least readable on the gray wire exiting the relay?? Have full 12v on orange wire coming in… but nothing readable on any of the leads going out! Part of the problem at least, I suspect??

  3. Certainly if you suspect the relay is bad you could swap it with one of the other ones that are next to it.

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