Any short to ground as the R22 is famous for could possibly do that , but that is b/c R22 comes off the key and is HOT all the time the key is on.. thereby causing a direct short....whereas , the aux fan R15 circuit is only on when the pressure switch at the drier is calling for low fan, and that low fan feed to R15 is FUSED at the low fan relay, so they likelyhood of a burnt wire at R15 effecting the ign is remote , as far as I can tell from schematics and experience...but I will not say " absolutely NOT " b/c I know there are going to be threads that disagree with that analysis and claim "YES"
...but you know how that always winds up.....no where.

ANY short on aux fan circuits should simply blow the fuses, be it high coolant fan or low a/c fan circuits. And the problem on R15 is usually on the low fan feed side b/c those wires are undersized from the relay to the R15. [ 2/5mm, as compared to 4.5mm for high fan]

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A Dalton