Gauges not working

[Georgia Boater]

I recently bought a 87 Glasstream Cutlass 172 with 3.0 MerCruiser. Got engine running but none of my gauges work on the dash (RPM.water temp,battery voltage) It has the old long fuses on the front panel that unscrews and you pull out and all of the fuses are good. the bilge pump and the exhaust fan both work fine and they are located on the dash as well. I traced the wires back to the main wire harness plug and then wiggled the plug and took it out and placed it back in but still nothing. The previous owner told me that the gauges worked last year just fine. Does anyone know if there is a mystery fuse somewhere or is it just possible that they are all bad. I would at least at a minimum get the water temp working and hopefully the RPM gauge before I take it to the water. I know I need to get multimeter out and test voltage on the gauges. Shouls all of these gauges read 12 volts. Any other tips on troubleshooting these are appreciated.

 

[Don S]

Re: Gauges not working

All of your gauges should be daisy chained together with a purple wire for 12V power.
The purple wire leading to the instruments should be powered from the I (ignition) terminal of your ignition switch.

 

[Georgia Boater]

Re: Gauges not working

Thanks. I will check it out. The previous owner installed an after market radio and that purple wire is going to the radio if I'm not mistaken. i will check it out when I get home this evening.

 

[Don S]

Re: Gauges not working

Thanks. I will check it out. The previous owner installed an after market radio and that purple wire is going to the radio if I'm not mistaken. i will check it out when I get home this evening.

It better not go to the radio, only engine and instruments go to the ignition switch. Radios and other accessories go to the fuse panel.
Sounds like the previous owner didn't have a clue what he was doing.

 

[Georgia Boater]

Re: Gauges not working

I looked at it last night the purple wire does not go to the radio. The purple wire is attached to the I terminal on the ignition switch. Should this purple wire go straight back to the wiring harness plug or is it tied into something else along the way like the neutral safety switch.

 

[Don S]

Re: Gauges not working

The purple wire goes to the lanyard kill switch, but that is usually after the insturments. But, since the engine runs, that isn't your problem.
Make sure the instruments have a good ground.

 

[Georgia Boater]

Re: Gauges not working

Ok. I will check it out.

 

[Georgia Boater]

Re: Gauges not working

No time to work on it. I just took it to a local marina and have them work on it for me. thanks for the input