Electrical Problem

[High Bidder]

Last year my boat developed a electrical problem and I need some advice where to look to what might be the problem. I have a 93 Striper IO. The problem is that when I turn on the nav lights or blower or any other current draw my gauges ( temp, oil pressure, fuel,) increase slightly and stay there until the switch is turned off and also my Voltage gauge drops. On a side note, last year I had to replace the temp gauge and I used a original equipment type. But when I replaced the gauge I cracked the plastic dash panel so I machined one out of aluminum. I also replace all the switches with new ones. Could the aluminum panel be the problem or do you think it is a ground issue. There were a lot of wires to reinstall but I carefully labeled each wire so I think I didn't go wrong there. But there is always that possibility. What do you think?

 

Thanks, High Bidder

[Don Supon]

Just a guess.

 

The aluminum panel is the problem and is sending current.

Isolate each gauge and switch installed into the aluminum panel with a gasket of rubber, etc. to be sure the panel itself is not transmitting from one gauge to others through the panel. Don't forget the screws holding the gauge/switch to the panel.

 

Another source to check is the wiring to each gauge and switch to see if connectors are touching each other or if somehow two wires to different gauges/switches are pinched together. Try to seperate any touching wires.

[seasquirrel]

Most gauges I have seen are non conductive material where they come in contact with the panel. Could be an issue but I would check your output in terms of volts coming out of your alternator. I am sure your voltage regulator is internal within your alternator. Could be putting out too much voltage. Should be about 12 volts. I had a striped that put out 14 volts and spiked gauges and ran like crap at higher rpm. Just another easy test that may help. Keep us posted.

[momay4000]

I agree with Don Supon - put a voltmeter on your aluminum panel to see if there is any stray DC voltage when you flip your Nav. lights, blower switch, etc. You should not have stray voltage on the aluminum panel, if you do, then you are bridging your gauges with the aluminum panel material. You will need to insulate your gauge that you made from aluminum with rubber or plastic.

 

A cheap voltmeter is worth its weight in gold in situations like this.

 

Good luck,

 

Chris

[Don Supon]

You could use a product named "liquid tape" to coat any metal surfaces that might contact the aluminum panel if it is determined that is the problem. Just paint it on.

[High Bidder]

Thanks for the replies. I never thought of testing the panel for voltage. I checked all the wiring connections and looked for faults in the coatings. Each gauge has a ground wire and I will have to recheck all those to make sure I have them on the correct post.

 

Thanks again

High Bidder

[jimski2]

Your voltage regulator puts out voltage according to your battery condition and load it is carrying. A fully charged battery should read about 12.5 volts and it has a 1.5 volt resistance internally. Your voltmeter will read 14 volts with the engine running and higher voltages like 14.7 volts to charge and carry the load you have connected to it. This may be where you see the increased reading on your gauges.

[Xxx]

Your voltage regulator puts out voltage according to your battery condition and load it is carrying. A fully charged battery should read about 12.5 volts and it has a 1.5 volt resistance internally. Your voltmeter will read 14 volts with the engine running and higher voltages like 14.7 volts to charge and carry the load you have connected to it. This may be where you see the increased reading on your gauges.

Jimski2 is absolutely correct, Your Bat. completely charged up should read 12.5 volts and the Alt. should be at minimal should be 13.8 to 14.2, This is a marine application, street apps. 14.2 - 14.8, the reason they run a marine at 13.8 is under NORMAL conditions is to keep the battery from over charging, with long period of time running with min. load to battery. Now once you add all the electronics and down riggers ect, the load you are putting on the battery the ALT, regulator will sense and it will put out more amps. and with more amps comes more voltage, this is normal. If you ever had a machine with a amp gauge when you run the starter it will show a negative swing in the gauge, when motor starts it shows a big swing to the charge side and as it runs it comes back to just about the center, just a tad to the positive side of the gauge, the alt. is doing the same game, just showing it in volts. All gauges are insulated so the only way you would have a draw coming from the metal plate is a leaky ground on one of the gauges, possible, but I would lean towards human error, a hot wire touching a ground just enough to effect the Instrument panel and not blow a fuse or breaker. Take the hot wire off each gauge one at a time to see if problem goes away, if nothing changes return the hot wire and go to the next gauge, so on then repeat same steps with the ground wires, if that doesn't cure the problem, then the problem lies somewhere else. Hope this helps F&F Starter & Alt. Owned & Operated by PAP.

[High Bidder]

The next thing I am going to do is draw a schematic of the wiring to all the gauges and tach. This will help me determine which wires are dash lights and which wires are gauge functions.  Another symptom is that the tach jumps if a switch is turned on if the engine is not running. I will have to test the alternator next time I run the boat. I still have a few weeks to work this problem out.

Thanks,