Community Forums

CraigTee · 10-11-2017, 12:28 PM

An intermittent problem last year has come back to haunt me;
All dash gauges bottom out with a message of "volt" on the dash LCD readout, no speedometer, odometer, air gauges.... nothing.

Symptom;
-----------
(after a couple of wet days)

1 Turn the key to "on" position.
all is good.... voltage gauge shows just under 13 volts, transmission digital readout and digital odometers show correctly.

2 Turn the key to "start" then back to "on" after engine engages.
everything dies and "volt' message appears.

Troubleshooting already done;
-------------------------------
1 Both batteries checked (separately), 12.89 and 12.9 volts
(engine not running)

2 Battery cables checked for corrosion.
.7 ohm maximum resistance end to end.

3 Alternator voltage checked while driving.
Averages 14.4 volts.

The "systems" ARE all working and in decent shape. Gauge connected to the rigs computer shows proper voltage, speed, RPM, oil pressure, etc. (ScanGauge)

The dash instruments GROUND is solid.... instruments function with key to "on" position prior to starting every single time. (unless there is a separate "battery ground" and "run ground"?)

Currently, everything has run normally for the past 500+ miles/8 days.

My Guess: A relay that switches the dash gauge power from battery to alternator once the engine starts.

Any other thoughts?
Anybody know which relay I would be looking for?
The "Ignition Relay" in the front driver's side compartment?
The "Ignition Relay" in the rear curb side compartment? Other?

Also, before I start my search, does anybody know offhand where the headlight relay is located? No headlights but "brights" work fine.

Thanks in advance for any thoughts on this.
Craig

onechaddude · 10-11-2017, 04:34 PM

Craig,

I've never had what you are saying happen to my 07 Neptune. However, about 5 to 6 years ago I had a similar issue. I could be driving along and all the gauge would drop back to 0. It was like I cut the switch off and back on. The engine would never stutter, just continued to run like normal. This would happen every once in a while. Sometimes it may do it a few times over a few minutes then normal for hours. One time we were coming down the interstate and the speedometer was off. It showed faster than I was going. It would speed up and woller around and just plain crazy. I decided then something had to be done.

I posted a thread on here and several folks commented that it was probably a ground problem. I pulled the gauge cluster out of the dash and ran a new ground wire. If you look in there, all the ground wires are daisy chained together. I found a good spot to tie in and simply attached a new 10 gauge wire into the series. I ran the wire through the firewall and grounded to a good spot above the generator.

Since doing this, only one time (knock on wood) have I noticed the gauges fluctuate like before. This h appened when I stasrted the genny soon after starting the engine. I assumed this was possibly caused by low voltage from engine start and engine alternator not putting out much voltage due to just starting up.

Hope this helps.

Chad

CraigTee · 10-12-2017, 09:15 AM

I believe I read through that thread prior to posting!

There were a lot of great suggestions that helped to guide me through the trouble shooting steps I outlined.

I have ruled out a bad ground (for now) due to the consistency of the symptoms. Key on, good instruments, start, dead instruments. When they were dead, I could repeat this scenario over and over without variation. This leads me to believe it's a power supply issue as opposed to a weak ground.

I also agree with your assessment on that one time failure after running your new ground. The generator can play havoc with the gauges if the battery isolater is powered. During my troubleshooting procedures I totally lost ALL power to the gauges (no "volt" readout in the the dash) after attempting to add assist via the generator.

Thanks for your post and, if it does come down to a ground, I will take a lesson from your experiences and duplicate your solution.

Hopefully somebody in here will have some experience or thoughts on the relays that power the dash in the "run" condition?

Thanks again Chad!

MSHappyCampers · 10-12-2017, 01:32 PM

Hi Craig!

Welcome to IRV2! We're sure glad you joined the gang!

Can't help with the problem but wanted to say hello. Keep her between the ditches!

Good luck, happy trails, and God bless!

66gt350 · 10-12-2017, 05:26 PM

Craig: Do you know if the turn signals work when the gauges aren't? My guess would be that they don't. If that is the case you probably have an ignition switch that is not coming back fully to the run position or the switch is not making a connection when it does. I wouldn't think it has a relay for that. They are usually run right off the ignition switch. When it happens again try turning the switch back towards the run position or wiggle it a bit.

Good luck
Jim

onechaddude · 10-12-2017, 05:30 PM

Quote:

Originally Posted by 66gt350

Craig: Do you know if the turn signals work when the gauges aren't? My guess would be that they don't. If that is the case you probably have an ignition switch that is not coming back fully to the run position or the switch is not making a connection when it does. I wouldn't think it has a relay for that. They are usually run right off the ignition switch. When it happens again try turning the switch back towards the run position or wiggle it a bit.

Good luck
Jim

Jim, that's a good possibility there. I hadn't thought of that. I've read on here quite a few folks having problems with the ignition switch once it has some age on it. I'll certainly keep that in mind if mine ever does it.

Chad

walt2137 · 10-12-2017, 06:49 PM

Craig i agree with Jim. But if you want to have all of the gauges with accurate readings i would susgest you look at the Silverleaf VMSpc system, monaco dash gauges are known to be basically inaccurate with a sorry ground system.

CraigTee · 10-16-2017, 11:25 PM

I apologize for my absence... finally arrived at the winter house to find that apparently CenturyLink didn't think I needed DSL til next month. Sometimes....... oh well.

Thanks for the welcome Joe!

Jim the signals WERE working... I wish they weren't because that would make it an easier fix. Everything but the instruments were functioning normally. The lowbeam headlights were out but the brights worked so I'm guessing headlight relay on that one.

I've driven the rig locally a couple of times and haven't had an issue. I'm thinking that I'm going to try Chad's suggestion and run a good ground... but not actually ground it... just run it. That way, if I lose the instruments again, I can simply bolt the ground down and see if it corrects the problem. If so, awesome.... if not, then I'll know I need to keep looking.

I was really hoping some one would say something like, "oh... that's caused by that pesky relay in the front cabinet!" (grin!)

Thanks again for the suggestions and I'd appreciate it if you'd keep tossing it around in the back of your mind and then post any additional thoughts you might have on it.... right now I'm kinda lost on this one....

Craig

flynnwalter · 10-17-2017, 08:23 PM

Craig
Several years ago we had lightning kill our jacks (which were down in standing water), step motor, and other items located beneath the coach. When I headed for service I discovered there were no gauges showing, either. It turns out the 'brains' for all gauges are in the speedometer, which took a hit. Replaced the speedo and all is well. I do not know why your situation would be intermittent, just wanted to give you a heads up to focus on the speedo.
Good luck!

CraigTee · 10-18-2017, 12:15 PM

... for the tip Frank! Will most definitely file that piece of information even if it ends up not coming into play in this situation.

Here's what bugs me about this thing:
(when the gauges weren't working)

Key on, got gauges... accurate trans temp, voltage, odometer, etc.
Turn to start, engine starts.
Back to key on, all gauges dead and "volt" reads out on the lcd.

Repeatable time after time without fail.
Engine off. gauges good.
Engine on, gauges dead.

Go figure....

onechaddude · 10-18-2017, 06:10 PM

Quote:

Originally Posted by CraigTee

... for the tip Frank! Will most definitely file that piece of information even if it ends up not coming into play in this situation.

Here's what bugs me about this thing:
(when the gauges weren't working)

Key on, got gauges... accurate trans temp, voltage, odometer, etc.
Turn to start, engine starts.
Back to key on, all gauges dead and "volt" reads out on the lcd.

Repeatable time after time without fail.
Engine off. gauges good.
Engine on, gauges dead.

Go figure....

Craig, in reading this post my first thought goes back to the ignition switch. Have you tried wiggling the key or even reaching under the dash and wiggling the ignition switch and the wires attached to it? Maybe give that whirl and see if any change.

Chad

CraigTee · 10-20-2017, 01:05 PM

After typing my last post, I thought "what if it's not making the connection as the key turns BACK in the other direction?"... seem like a possibility.

Just two pieces of evidence argues against an ignition switch:
1. the turn signals still function.
2. the only time I had a consistent/recurring problem was in rainy conditions... the ignition switch should not have been affected... especially after driving some time with the interior heater on.

One last thing that makes this tough to troubleshoot.... once the gauges fault out (lcd reads "volt"), I must shut the engine all the way off and then restart it to get them back. This happened last year when the problem first occurred and then again this time as the gauges started coming back to life.

It's like a switch gets flipped that requires a complete engine shut down and restart to fix. That may be why wriggling the wires never had any effect.