Related issues?

Topic: Related issues? (Read 806 times) previous topic - next topic

Related issues?

May 21, 2020, 10:50:43 pm

I've got a little list of items that aren't working properly and I would like for them to.

1. Fuel gauge never goes above about 3/4
2. Boost gauge doesn't go above 10psi (silverleaf shows 28 maybe)
3. Temp gauge shows about 220-250 and sometimes pegs out all the way to the right. If you give it the old tap trick it bounces all over the place. (Silverleaf shows just under 180) also I believe the engine fan controller has gone bad and is unplugged.
4. Oil press shows about 20 psi at cruise. ( silverleaf shows +/-35psi)
5. Odometer and trip meter digits are unreadable
6. Sometimes flashing headlights on smart wheel engages wipers or turns off cruise
7. Retarder is intermittent. Sometimes it works when you first start off and sometimes I have to stop and kill the engine and restart it and that usually gets it going again. Sometimes I'll come to a complete stop (like to get fuel) without killing the engine then get back on the interstate and the retarded has quit again.

Re: Related issues?

Reply #1 – May 21, 2020, 11:01:37 pm

A bad ground would be at the top of my suspects list.

P.

Re: Related issues?

Reply #2 – May 21, 2020, 11:08:53 pm

Thanks Pierce, that's kind of what I was thinking. I don't even know where to start looking.

Re: Related issues?

Reply #3 – May 21, 2020, 11:27:06 pm

Yes it's all related to being old!!

Just tackle one at a time and you will get through them in time.

Re: Related issues?

Reply #4 – May 21, 2020, 11:29:47 pm

Our ground for many items is under the flip up dash top. Yours is different so will need the advice of an owner of a like coach. Once you find the ground, you can check for anything loose in the fasteners/wires. You can also bring in a jumper cable with one end to the steel chassis and the other end close to the ground for the dash components. Then use a multimeter on the Ohms setting and see what if any resistance there is between the chassis ground and the instrument panel ground.

Pierce

Re: Related issues?

Reply #5 – May 21, 2020, 11:51:07 pm

Also check your engine ground. With a bad or loose engine ground cable, sensors may give incorrect information to gauges, Try running a jumper cable from the chassis to something steel on the engine like the exhaust manifold or engine lift hook.

Pierce

Re: Related issues?

Reply #6 – May 22, 2020, 08:05:49 am

Thanks again Pierce. I'll check them out.

Re: Related issues?

Reply #7 – May 22, 2020, 08:59:28 am

Quote from: Pierce & Gaylie Stewart – May 21, 2020, 11:29:47 pm

You can also bring in a jumper cable with one end to the steel chassis and the other end close to the ground for the dash components. Then use a multimeter on the Ohms setting and see what if any resistance there is between the chassis ground and the instrument panel ground.

Pierce

I think it's safer for the multimeter and easier to probe the ground connection with power flowing. Any voltage showing across the ground connection is indication of a poor ground.
And the last time "I" let the magic smoke out of a multimeter, it was my fault because "I" left the test leads in the Ampere sockets and Lynn used "his" meter to measure voltage. All my fault.

Re: Related issues?

Reply #8 – May 22, 2020, 11:14:52 am

Quote

I don't even know where to start looking.

Most of the automotive grounds are in the dash area. Just raise up the cover and look to the left for a bunch of green wires. Here's a photo of the grounds on our 99 320.
jor

Re: Related issues?

Reply #9 – May 22, 2020, 12:03:28 pm

My guru buddy pulled the gauges wires off them and squeezed there ends tighter then reinstalled them.

Re: Related issues?

Reply #10 – May 22, 2020, 01:34:08 pm

DJ,
You have problems with several items that go to that same ground bus. Seems unlikely they all developed a bad connection around the same time.
Think I would start by checking the connection on both ends of that braided ground strap on the bus bar. See if anything changes.

Re: Related issues?

Reply #11 – May 22, 2020, 02:27:58 pm

Quote

Quote
I would start by checking the connection on both ends of that braided ground strap on the bus bar.

Great idea from John. Here's a couple of photos. One shows the dash end of that braided strap and the other where it is grounded. You will likely find that end of it in your middle compartment behind the white fiberglass cover. Yours will look similar to this one but with lots more stuff.
jor

Re: Related issues?

Reply #12 – May 22, 2020, 02:50:34 pm

Quote from: jor – May 22, 2020, 11:14:52 am

Most of the automotive grounds are in the dash area. Just raise up the cover and look to the left for a bunch of green wires. Here's a photo of the grounds on our 99 320.
jor

Thanks, I guess I did know those grounds were there. Yours is a lot cleaner than ours.

Re: Related issues?

Reply #13 – May 22, 2020, 02:59:58 pm

Thanks a lot guys. I'll check both ends of that and maybe take them off and take a wire brush to them for good measure. It also has trouble firing the engine. I would say most of the time. It's done it off and on since we purchased it a couple years ago. I wonder if this is also related?

Re: Related issues?

Reply #14 – May 22, 2020, 03:19:48 pm

Quote

It also has trouble firing the engine.

I'd do like Pierce suggested and check the chassis ground. My recommendation is to find every ground on your rig, take it apart, wire brush it and reinstall. Find where big black cable attaches to the frame and to the starter and of course, at the batteries.

For example, here's a list of grounds on our current rig which is a 97 270.

AT ENGINE (rear left side)
B22
B23
Alternator

AT MIDDLE 12V PANEL
B6
B22
Braided Wire

AT COACH BATTERY COMPARTMENT LUG
B22 from inverter

START BATTERIES
000 B2 to the starter
000 B6 from the starter to middle 12 volt panel lug (joins B22)
Braided wire runs from middle lug to ground panel under dash. All the dash grounds connect here.

COACH BATTERIES
B8 from inverter to shunt
B22 from inverter to ground lug
B22 from ground lug to left side of shunt (joins B8)
B8 from right side of shunt to battery
jor

Re: Related issues?

Reply #15 – May 22, 2020, 03:40:26 pm

Quote from: jor – May 22, 2020, 03:19:48 pm

I'd do like Pierce suggested and check the chassis ground. My recommendation is to find every ground on your rig, take it apart, wire brush it and reinstall

Thanks again. I'll get the big book out and do a deep dive and get my grounds cleaned up. We had it at MOT not too long after we got it to replace the slide seal and the airbags. They also checked the cables for the starter. But I'm not to confident that they did a real good check. Several of the bolts in the bottom of the airbags were only finger tight and two of them had leaks at the 90s on top.

Re: Related issues?

Reply #16 – May 22, 2020, 06:25:11 pm

Thanks for the info Jor!

Still learning and this was definitely one of the great mysteries for me. Not sure I have had any problems related to the ground but have read many threads about grounding problems. I usually had a blank stare....now I have a little clarity on the subject!

Re: Related issues?

Reply #17 – May 22, 2020, 07:02:51 pm

Yep Jor just showed me a couple things about my 270 I wasn't sure of.

Re: Related issues?

Reply #18 – May 24, 2020, 11:43:30 am

I use dielectric grease on my electrical connections. Keeps water out, and decreases corrosion. Thanks Jor for posting the ground connections.
After 20 years these connections have issues. Getting old. A wire brush and some dielectric grease can give them a new life. Shut off the batteries when doing this. Either with a switch if you have them or by removing the cables.

Re: Related issues?

Reply #19 – May 24, 2020, 06:09:38 pm

Any grease works fine. Dialectic does not conduct.

Also the dash ground can work better if you drop an additional ground strap out the bottom of the dash to the frame ground post. They are near the headlight connections.

Re: Related issues?

Reply #20 – May 25, 2020, 12:10:26 am

Old Foretravels had the chassis as the ground side. Later coaches had green ground wiring run to every fixture as far as I understand

Re: Related issues?

Reply #21 – May 25, 2020, 09:09:14 am

Quote from: Protech Racing – May 24, 2020, 06:09:38 pm

Any grease works fine. Dialectic does not conduct.

Also the dash ground can work better if you drop an additional ground strap out the bottom of the dash to the frame ground post. They are near the headlight connections.

That's a good idea too. I saw some conductive grease on the internet. I wonder if that would be good?

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