SPEEDOMETER GOIN CRAZY

[makaveli911]

when my sub hits the speedometer goes up like 10 mph but not the rmp's. So i dont know how fast im goin. It use to only happen when the volume was at like 25-40 but now it happens at like even 10. Also it makes a humming sound too that i hear when im goin faster than 35 mph (also when i go faster than 35 mph thats when the speedometer goes real crazy).

 

[leenjen]

i dont know much about it, but i heard there was a speedometer gear. maybe the gear is loose??...

 

[91'explorer 2wd]

mine twitches on the way up. it's kinda funny cause everyone makes fun of how it's the little explorer that could. your speedometer sounds like it's going haywire though.

 

[PsykoTone]

mine did the same thing, the 2 15's would puond and it would jump back and forth, I talked to a friend who owns an audio shop and we replaced the Alt., put in a yellow top and ran a second battery for my amps. he thought it was robbing the voltage, when the subs hit. my voltmeter confirmed that. after all that it worked as it should. then again we went through and tightened everything, and replaced fuses and relays. now it only acts funney in the mourning, when it's cold. it rises with RPM's (not the way it's supposed to) my therory on this is that the cold is allowing "cross talk" between the wires. hope you figure out what it is. PS try unpluging your amps, drive around and beat on the dash. if you hit the dash and it acts funney. It's a loose somthing on the speedo, if it works fine try a high output Alt. There may also be somthing wrong with the amp.

 

[TDG]

I'm guessing that the speedometer on the early model explorer is cable driven, if that is the case then electrical gremlins from audio systems shouldnt cause any problems with your speedometer readings. The twitching problems are probably being caused by lack of lubrication in the cable causeing the inner part to bind rather than turn smoothly. As far as the needle bouncing around with bass I cant help you there but I don't think it is related to anything electrical.