chassis electrical replacement

[Isuzusweet]

The biggest worry I have is an electrical fire.

The biggest problem I seem to be having with the Mistress is her lack of "spark"ling demeanour. A new radio is installed and I loose my marker/parking lamps. Get the marker/parking lamps fixed and lost my radio. I have burnt fuse holders with wires going to new inline fuses installed by PO's, a volt meter gauge that goes hard right at start up and the only life I see from it is when I turn on the indicators as it flicks in time with them; and spaghetti under the dashboard. Oil pressure and volt gauges are flickering and untrustworthy. Factory grounds are corroded and giving me grief.

What would it take and would it be worth it to replace the Chassis wiring harness on a diesel 310?

Cheers

[dljosephson]

You could come here and we could do two of them together. Before all my issues with brakes and suspension I thought this would be my main issue. Now I'm back to it. I'm an EE and have wired many aircraft. The 310 wiring is just old tired stuff that has been butchered by two POs and many frustrated mechanics. I won't go overboard with aircraft wiring practices but ohh, man, there is a lot of crust there. I will start with a ground reference point and work from there. It is really pretty simple but we are going to need to ditch nearly everything that's there. Fortunately the engine runs fine without any electrical at all...

One problem I noticed is that Airstream seems to have done some odd things to the GM factory fuse block, some extra goop on the firewall side and so on. We might want to remove everything but factory chassis wiring from that, get that stable and then move on to gauges as a separate system, since fw of the gauges are GM standard anyway.

[idroba]

I wish I could be more positive. Having had a Gas '83 310 and having a good friend with a Diesel '81 280 I have looked at a lot of Chev/Airstream wiring in those era motorhomes.

The original wiring (as you know) was marginal when they were built. And now they are 30 years old or more. Age does not improve them.


To replace it all of course could be done but it would take a real electrical expert to do it. I am sure no original wiring harness exists so each and every wire would have to be individually replaced, an exceptionally difficult and time consuming process.

However, the wires themselves seldom go bad, even old insulation holds up very well. What I might consider would be to replace not the wires but the ends of the wires, that is all of the switches, connectors, bulbs, sockets, fuse blocks and the like. Each wire terminal would be replaced with new. All ground points would be replaced with the best system you could devise, including star washers and maybe even dialectic paste, and bolts (not rivets or self taping screws) to hold them in place. Maybe even an entire new ground buss wire(s) system which was never there to begin with. Of course, any questionable wires would be replaced, especially those under the doghouse and near the engine.

That job would still be time consuming and expensive if someone else is paid to do the work, but less than a total re wire job.

In the mean time or as a minimum, be sure all fuses and fuse blocks are good. With that and the proper fuse size, I think the danger of a fire is minimal. But, things that the PO (s) have added are especially important to inspect, along with the wiring that was done.

My ideas are just tentative. I am not sure what I would do if I still owned my 310. Maybe that is one of the reasons I no longer have it. Old motorhomes of any brand are a handful to take care of and keep operating.

You do have my sympathy and understanding, but no magic solution.

[Punch]

As you intimated above, grounds are the issue. Before even considering replacing part, let alone all, your harness, get the grounds good.

95% of electrical problems are due to grounds. 99.75% of weird electrical symptoms are due to grounds.

Did I mention that you should get your grounds in good order?

Oh, and see if you can get Ontario to stop spreading salt in Winter. That would help too.

[Kota]

My only experience is with the 360 Classics on Spartan Chassis. On thing AS didn't skimp on is the gauge and quality of wire. The production line wiring is quite well done. That is about where it ends. The final wiring of hooking the body to the chassis and installing options looks like it was done in a hurry with very poor craftsmanship and poorly documented.

I had to chase down and label a lot of wires to start straightening things out. Bad grounds and poorly crimped connectors were the big culprits. The wiring under the dash adding the options like radios, back up cameras, ... is an incredible rats nest of wire and low quality smash on connectors. I always use the bare metal connectors with the proper factory quality die and cover them with shrink tube.

For some reason the installers think it's ok to screw a ground terminal to the body on top of carpeting. This nearly lit off on the ground to the HWH leveling system. Several of my problems with battery charging and other systems like the water ump were due to bad grounds.

My issues with the horn and turn signals were all due to poorly crimped connectors and loose bonding screws and nuts.

I would start by going through end to end and redoing all of the grounds. Replace the crimp on terminals, clean up the surfaces where they screw or bolt down, and hit the new ground with a dab of paint to seal it. Then start on the other connections one system at a time. Label the wires you track down and check all the terminations and couplers. Check for rub spots and secure loose floppy wires with tie wraps.

I've spent years chasing electrical problems on aircraft, industrial equipment, vehicles, ...

I hate crimp ons and stake on connectors. They are usually the source of problems. And if the prob looks messy and unorganized, it is.

Good luck!

[mayco]

Its frustrating no doubt Tony. The chassis electrical system on the 310 is perhaps the weekest link in the whole rig. When I saw the extensive use of the blue snap connectors by the factory I knew there was going to be lots of problems, they suck. But to undertake a complete rewire, and do it yourself, would be wayyy too much for me I know that. There is just so much going on with their electrical system, that seems to be unique to the individual vehicle, that it would drive me nuts. If there exsisted a decent reference guide or schematic it would sure help.

What Ive tried to do is deal with each individual problem as it arrises and clean things up as I go. The first thing I did was to disassemble the ground straps to the frame and clean those up real well. My latest electrical issue was that the heater blower wouldnt run on the "high" setting. Its been that way since Ive had the rig. I got it to work but had to run a new wire from the post on the switch to the blower. Its just one thing after another with the wiring on these rigs.

I guess for me, I would rather deal with the individual problems as they come up and keep the rig on the road so we can actually use it.....and we have been.

I know that you hate the electrical part of your renovation, it IS frustrating at times. But to do a complete rewire?..............man, big bucks to pay someone to do it and would take forever to do it yourself. I know for me its just too much to contemplate.

Mike

[mayco]

As far as fires go........at least its not a gasser

[J. Morgan]

Many times I have just started over from scratch when the factory wiring is overly butchered.

I always preferred the Ron Francis kits.

https://www.ronfrancis.com/




Brevi tempore!

[mayco]

If it was a standard factory harness that would be an option but I think the main problems with these is the interface between GM and the Airstream systems.

[J. Morgan]

Sometimes when people have "fixed" and "fixed" and "fixed" old wiring over and over a fresh start is the easiest path to safety and reliability.

The kits I referenced above have labeled wires along their entire length, and numbered connections at a central fuse and distribution panel.

FWIW, (assuming the chassis uses a GM system) normally the high fan speed current does not run through the dash switch but the dash switch controls a relay under the hood for the high speed fan setting.

In stock form, low, med low, and med high settings are protected by one fuse, and the high fan setting is protected by its own separate fuse.

The wire for the high speed fan is normally ten gage, the relay is to protect the fan switch from the high current that the fan draws on high speed.


Brevi tempore!

[mayco]

J Morgan you obviously know your stuff about automotive electrical, maybe we could all hire you as a consultant on these beasts. The HVAC on the '82 310, and many more I think, is pretty challenging to say the least. The heater blower portion is Chevy and the cooling system is ACME I think. Two different control systems for each, just another example of how weird the dash wiring is on the Classics. To top that off, I have read that the heater slide controls and switch are Dodge. Hehehehe, Im not sure of that but its what Ive read. There isnt any detailed diagram or schematic that Im aware of. (I probably couldnt read it if there was). Just an example of what Tony and the rest of us are faced with when trying to troubleshoot. Someone with your automotive electrical knowledge would have a much better chance at nailing some of these problems down.

Ive found that I just try to start with the simplest repair first, usually grounds, fuses, connections etc.. Sometimes its poke and hope, sometimes the problem is obvious.

On my heater blower, its my understanding that the low and medium fan speed run through a resistor and the high speed is full 12v to the motor. I couldnt find reference to a relay and at the motor there is one hot #12 and the ground that is tied to a mounting screw about 6" from the motor. I will investigate further.

Mike

[J. Morgan]

We might have to work something out! I love working with old fashioned pre "computer everything" automotive wiring. Over the decades I have gotten pretty good at figuring out old systems and making them work reliably.

It sounds like the manufacturer found components that would fit the vehicle, and then forced them to work together. Which is ok till someone tries to figure out how it all fits together.


Brevi tempore!

[dadstoy]

Now, now Mike! Not everyone is a "gasser" hater!

Originally Posted by mayco

As far as fires go........at least its not a gasser

[mayco]

Hehehehe, all joy Dean!!! Just reference to the risk of fire under the hood. (Im still trying to find the plug wires on the Isuzu)

[dadstoy]

Originally Posted by dljosephson

Airstream seems to have done some odd things to the GM factory fuse block, some extra goop on the firewall side

I always wondered if that was "factory" or not...not going to wonder about that one anymore!

[dadstoy]

Just teasing ya!

Originally Posted by mayco

Hehehehe, all joy Dean!!! Just reference to the risk of fire under the hood. (Im still trying to find the plug wires on the Isuzu)

[dadstoy]

Tony,

The MH wiring can seem to be daunting, but I don't find it that difficult...it's just time consuming to troubleshoot. I wouldn't replace the wiring, but instead would take the time to fix the issues you have.

A few yrs back when I had the entire dash out for painting and ductwork replacement, I was amazed at the spaghetti wiring behind the gauges, but I was also amazed how the wiring was in such good condition. A few issues that I saw and dealt with were connections on the gauges and switches.

I agree with many here that the biggest issue with the wiring is broken, loose or corroded grounds. That is what most of my gremlins have been.

[Isuzusweet]

Thanks all for the replies.

It just that every time somebody fixes an electrical system on my rig they seem to find power from somewhere or something else, add a fuse and string new wire to the system without power. At some point I think I'm going to have to pull everything, grab a new bigger fuse block and start pulling wire myself. It will probably drive me to drink or a close relationship with Xanax but not doing something is an failure waiting to happen.......again and again. This year I lost an electrical system every trip, if not two.

It all started with the burn't out fuse that sent power to the infamous yellow wire. What was Airstream thinking that a 18 gauge wire run 30+ feet would be able to supply enough power to run an air compressor, in heat and not blow?

If I did do this I would probably start replacing wire and rewiring systems BEFORE ripping out the old wiring. As each system works, go on to the next.

It's depressing looking under the dash and seeing fuses just hanging in space, no labels or explanation of what they control.

Frustrated! Heck I'm even thinking of taking an automotive electrical course this winter........

Hey! great idea.....Maybe I should approach an automotive school and ask them if they would consider the project as a lesson for students?......First question out of the kids mouth is going to be....Sir, where's your OBD connection for my code reader?

Cheers
Tony

[dljosephson]

I'm not sure grounds are 95% of the problem. In my experience, bad grounds and bad crimped connections are about equal. Oh and those blue 3M (originally) snap connectors, please tell me those didn't come from the factory...

I have a hunch that re-doing the dash wiring and removing everything that's piggybacked into the GM vehicle junction block will solve most of the flakiness. Just looking at the dash wiring drawing on page G-15 of the manual is scary, but it's easy to fix given some patience. Might replace some gauges in the process. And then, when you replace all the clearance, running and turn lights with LEDs, get rid of all the flaky connectors. That's the plan, anyway...

A very important part of the process is to use real crimp connectors and crimper. You want the terminals that have two concentric metal barrels and translucent nylon sleeves. They are made to military specification and cost 40 cents to about $1.25. The right AMP or T&B crimper costs about $200 (the military version is about $600) but there are good ones for about $40. Once you have used these you may throw the rest of the terminals you have in the trash.

[Punch]

I must say that I think well-crimped connections are fine, given dry and salt free conditions. But once moisture, and especially salt-laden moisture, gets at crimped connectors it migrates between the strands and soon you have a white/green mess. Soldered connectors are better under these conditions, but still corrosion happens. And corrosion will always happen under grounds.

Under my dash, everything looks completely chaotic, but in good shape. I would have said the quality of materials was excellent, although some things look a bit slap-dash in installation. This vehicle was not assembled by robots. I don't see any 3M snap connectors on what looks like original wiring, but a couple of later add-ons do have them.

We must always remind ourselves that none of our vehicles, even going back to the earliest Argosies, were designed to last anywhere near this long. I am sure they built them for the second or maybe third owner, with 15 years in mind max. My chassis is 27 years old and my coachwork a few months younger. I am now finding the shortcuts and design faults that the guy who paid $150,000 was never aware of.