Gauge illumination switch killing engine

[PentaParker]

I have a pretty basic Volvo penta gauge set from the late 90s. A rectangle of black plastic that has two fuses built-in at the top and also a light switch that illuminates all the gauges.

Keep in mind that I recently pulled my engine, and reinstalled it. During that time I redid the grounding studs at the back of the engine and put all the grounding wires on the studs with stainless nuts.

On random occasions, when I hit the light switch on the dash it will kill the motor and all the gauges will turn off. It’s almost the identical effect of what happens when you pull one of the fuses out of the panel. Sometimes it will do it five or six times in a row, then other times the lights will come on behind the gauges.

I’m hoping somebody might chime in and tell me it’s likely a defective switch. I thought basic switches just form a circuit and I’m having a hard time understanding what could go wrong in a switch that creates such a problem that everything wants to shut down.
Wondering if this is likely a faulty switch or more than likely something to do with the new grounds that I reinstalled. The two grounding studs were on the bell housing on the back of a 5.7 L gas Volvo penta.

 

[makomark]

sounds like you have two issues: 1) something is not wired correctly and 2) something is intermittent regarding its function (maybe a switch).

Maybe start with a good inspection of the wiring around the instruments. If that has no errors, I'd be inclined to isolate (disconnect) the gauge panel's 12VDC connections and go from there...

 

[Oldsaltydog]

Where does the switch get it's power from? If it's connected to the ignition switch on the same pin as the pin that powers the ignition and other things, then a bad switch could definitely be grounding those other things out.

 

[jimn]

Check the voltage on the purple wire from the ignition switch with the engine off. If the voltage drops significantly when you turn the gauge lights on, check all of the wiring on the gauges- if any studs with a purple wire also has a blue wire on it, look at the back of the gauge and correct it.

Measure the voltage on the purple wire at the coil- if you see a sharp change when the lights are turned on, something is wrong.

 

[sandkicker]

Just often enough the terminal lugs themselves on the wire ends get intermittent and the only fix is a replacement.. Check your ground connections.... need to be bright and shiny...as do all of the terminals... When you can get the engine running, wiggle the wires in the panel at their connection points and see if that will let you ID the culprit. Not likely a switch problem.

 

[jimn]

I'm both surprised and not surprised the marine industry manufacturers haven't adopted better terminals over the years WRT moisture intrusion. Connectors (a group of terminals in one organized cluster with a male and female end), sure- they now use Deutch connectors for gauges and engines that were sourced from GM use Weather-Pak connectors but they should have started using Heat N Seal terminals a long time ago. They definitely cost a lot more, but they're far more reliable and as long as the person making the connection knows how to crimp correctly AND uses the proper tool, they're very reliable.

FWIW-when I was at Mastercraft training, we discussed terminals/connectors and how to make proper crimped connections- many component manufacturers use some kind of hydraulic/solenoid activated machine and the crimping pressure is far higher than someone can produce with their hands. In testing, the machine-crimped connections are as good and as reliable as a soldered connection but don't run the risk of being a 'cold solder joint'.

 

[sandkicker]

I'm both surprised and not surprised the marine industry manufacturers haven't adopted better terminals over the years WRT moisture intrusion. Connectors (a group of terminals in one organized cluster with a male and female end), sure- they now use Deutch connectors for gauges and engines that were sourced from GM use Weather-Pak connectors but they should have started using Heat N Seal terminals a long time ago. They definitely cost a lot more, but they're far more reliable and as long as the person making the connection knows how to crimp correctly AND uses the proper tool, they're very reliable.

FWIW-when I was at Mastercraft training, we discussed terminals/connectors and how to make proper crimped connections- many component manufacturers use some kind of hydraulic/solenoid activated machine and the crimping pressure is far higher than someone can produce with their hands. In testing, the machine-crimped connections are as good and as reliable as a soldered connection but don't run the risk of being a 'cold solder joint'.

For decades ( since the 60s as I recall) the Military has specified crimped connections for wires. A hand held ratchet ( aka controlled cycle) crimp tool, properly used works as well as the hydraulic/solenoid types. The hydraulic/solenoid type are just used in high volume applications for speed and to reduce operator fatigue. Of equal importance is the type of wire used.... I once rewired a boat that the BOAT MANUFACTURER ( shame on you Pr######r) used speaker wire to wire the nav lights, i.e. plain copper wires. These days every marine supply store carries both plated wire, i.e. every copper strand is plated as well a plated terminals. Also available are plated terminals with integrated heat shrink insulation. And yet folks who spend hundreds of dollars on a fishing reel will buy the cheapest automotive store or big box hardware store terminals and wire to install a $1000 GPS/Sonar or VHF radio. I always use marine grade with shrink insulation terminals for all wiring on a boat and not just for the in the bilge stuff.

 

[jimn]

For decades ( since the 60s as I recall) the Military has specified crimped connections for wires. A hand held ratchet ( aka controlled cycle) crimp tool, properly used works as well as the hydraulic/solenoid types. The hydraulic/solenoid type are just used in high volume applications for speed and to reduce operator fatigue. Of equal importance is the type of wire used.... I once rewired a boat that the BOAT MANUFACTURER ( shame on you Pr######r) used speaker wire to wire the nav lights, i.e. plain copper wires. These days every marine supply store carries both plated wire, i.e. every copper strand is plated as well a plated terminals. Also available are plated terminals with integrated heat shrink insulation. And yet folks who spend hundreds of dollars on a fishing reel will buy the cheapest automotive store or big box hardware store terminals and wire to install a $1000 GPS/Sonar or VHF radio. I always use marine grade with shrink insulation terminals for all wiring on a boat and not just for the in the bilge stuff.

Having worked on many brands of boats, I was appalled by the expensive ones that had absolute crap for wiring and terminals. Tinned wire isn't expensive, but boat owners being notoriously cheap, will stop at nothing to get the best price.

I had a ratcheting crimper and the metal failed at a bend near the dies, so I put it away for a long time. Then, I decided to see if I could find a reasonably-priced replacement and found that Gardner-Bender had bought the brand that I had, so I called and asked if I could buy just the crimper without the dies since they're the same as what mine had. The guy asked for my address because he said they still honor the old brand's warranty. I just about passed out.

I did car audio & security for about 20 years and over that time, I estimate I made over a million crimped connections- with the crimpers I have used, the wire will fail before any of the strands slide out and I proved that to a, FNG I had hired. He came from a place that used wire nuts for most connections and when I TOLD him to get them out of my shop, he said "No, they work great!". I said that it's not his call because it wasn't his shop, it wasn't his lifetime installation warranty and that if I ever saw him use them again, he would be fired on the spot. He still wanted to try to convince me, so I handed him a piece of speaker wire, telling him to connect his ends with the crappy little wire nuts and I used a crimp cap, then we pulled on them to see which held better. The little wire nuts spun off and the ends were intact, the crimped wire strands failed and the cap never lost its hold.

I use this- the stainless version lasts much longer than the old steel one, which I had to replace every year because they would wear out.

Pro Grade ArmorEdge 3-in-1 Wire Stripper/Crimper/Cutter, Stainless Steel, 8.25" Symmetric Handle, 10-22 AWG, 1/Ea

ArmorEDGE wire stripper by Gardner Bender is designed to strip and cut solid and stranded wire. Envisioned to provide the user with the ultimate comfort and control these stippers offer ergonomic cushioned handles with dual gripping positions for traditional or forward hand positions ensuring...

www.gardnerbender.com

 

[PentaParker]

Having worked on many brands of boats, I was appalled by the expensive ones that had absolute crap for wiring and terminals. Tinned wire isn't expensive, but boat owners being notoriously cheap, will stop at nothing to get the best price.

I had a ratcheting crimper and the metal failed at a bend near the dies, so I put it away for a long time. Then, I decided to see if I could find a reasonably-priced replacement and found that Gardner-Bender had bought the brand that I had, so I called and asked if I could buy just the crimper without the dies since they're the same as what mine had. The guy asked for my address because he said they still honor the old brand's warranty. I just about passed out.

I did car audio & security for about 20 years and over that time, I estimate I made over a million crimped connections- with the crimpers I have used, the wire will fail before any of the strands slide out and I proved that to a, FNG I had hired. He came from a place that used wire nuts for most connections and when I TOLD him to get them out of my shop, he said "No, they work great!". I said that it's not his call because it wasn't his shop, it wasn't his lifetime installation warranty and that if I ever saw him use them again, he would be fired on the spot. He still wanted to try to convince me, so I handed him a piece of speaker wire, telling him to connect his ends with the crappy little wire nuts and I used a crimp cap, then we pulled on them to see which held better. The little wire nuts spun off and the ends were intact, the crimped wire strands failed and the cap never lost its hold.

I use this- the stainless version lasts much longer than the old steel one, which I had to replace every year because they would wear out.

Pro Grade ArmorEdge 3-in-1 Wire Stripper/Crimper/Cutter, Stainless Steel, 8.25" Symmetric Handle, 10-22 AWG, 1/Ea

ArmorEDGE wire stripper by Gardner Bender is designed to strip and cut solid and stranded wire. Envisioned to provide the user with the ultimate comfort and control these stippers offer ergonomic cushioned handles with dual gripping positions for traditional or forward hand positions ensuring...

www.gardnerbender.com

Thank you for the story, and I certainly will check some of the cramps on my gauges. I am just not that great understanding electrical and I have second-guessed all the grounding wires that I did at the back of the block or if it’s just a switch going out.