Horn and instrument guages

[jimrockireland]

I have a 1983 Wellcraft 196 Sunhatch with a Mercruiser MCM228R 5L engine (Serial#6275628). The horn was not working so I cleaned it out and backed off the adjusting screws to get it going. I noticed when I sound the horn my instrument guages all peg to the right. Is this normal? It doesn't seem to hurt anything and I have only tried this with the engine off.

 

[glenn property of pam]

Re: Horn and instrument guages

no something is wrong if that happens.

 

[jimrockireland]

Re: Horn and instrument guages

I'm thinking when I switch the horn on I am grounding all the sender units "S" terminals which I think is the condition for pegging the guages to the right.. I'm not sure how the horn itself is working. Perhaps it works equally well if the +12V and the GND connections are reversed.

 

[glenn property of pam]

Re: Horn and instrument guages

all the "s" terminals are not connected to each other so the horn should be able to affect the gauges that way. I would have thought that the horn is bleeding a small amount of voltage to the cases of the gauges/dash or the horn is wired incorrectly and is some how in series with the gauges. First thing to try is to unwire the horn then press the button and see if the gauges peg or something else happens.

 

[jimrockireland]

Re: Horn and instrument guages

Thanks for the info. When I get back to it next week I'll take a look at it and maybe re-wire it.