1988 120 johnson no voltage to purple wire on alarm.

[gmortie3rd]

Wondering what could be at fault.

No voltage at purple wire and low voltage on brown wire at alarm when grounded.

Also how many volts should be going to vro no oil sensor??

Thanks!

 

[saltchuckmatt]

Where are you testing, control box or motor plug?

 

[saltchuckmatt]

Could be this...

https://maxrules.com/graphics/omc/wiring/1988_89_120_140.jpg

 

[gmortie3rd]

Could be this...

https://maxrules.com/graphics/omc/wiring/1988_89_120_140.jpg

Yup, looked at this but the alarm isnt on the diagram. Previous posts mentioned voltage beong present to bothe the brown and purple wire with key in on position

 

[gmortie3rd]

Where are you testing, control box or motor plug?

Control box, the clips that plug into the alarm.
And the male side plug that plugs into The vro oil sensor.

 

[saltchuckmatt]

Didn't answer post 2. I believe the purple wire hooks to ground on the horn. Horn is polarity protected. Test the horn to 12 volts.

 

[saltchuckmatt]

Horns die regularly.

 

[saltchuckmatt]

No I'm wrong, purple is positive but key needs to be on and in neutral maybe. Now I'm brain farting.

 

[saltchuckmatt]

Post model number. Nevermind, do not need it.

You should have hot to purple if grounded correctly. If your trying to go through the horn and it's defective than that's your problem otherwise you have a wire or corrosion issue.

 

[gmortie3rd]

Post model number. Nevermind, do not need it.

You should have hot to purple if grounded correctly. If your trying to go through the horn and it's defective than that's your problem otherwise you have a wire or corrosion issue.

Horn is burnt out. Horn was removed when testing. Brown wire to ground was 4v i think? And purple to ground was 0.

Note i had the wires on the port side temp senspr switched for a bit after replacing computer. Could this have fried that circut that feeds the purple wire? Or is there another common cause?

 

[saltchuckmatt]

Horn is burnt out. Horn was removed when testing. Brown wire to ground was 4v i think? And purple to ground was 0.

Note i had the wires on the port side temp senspr switched for a bit after replacing computer. Could this have fried that circut that feeds the purple wire? Or is there another common cause?

On your tester....where did you hook up your ground? The brown wire? If so, ground to the battery and turn the key on and test the purple wire. If there is no power replace key switch.

 

[gmortie3rd]

On your tester....where did you hook up your ground? The brown wire? If so, ground to the battery and turn the key on and test the purple wire. If there is no power replace key switch.

Black was to was to ground. I have a good ground to the hull.