[mervifwdc]

Hi Folks,

we hit a new problem today while driving. some of the dash warnings lights blinked on and off, about the same speed as an turn signal. The power also went on and off from the rev counter. It did this about 8 times, then was fine again.

it happened again 20 minutes later.

we've since pulled in (somewhere with wifi!), and I'm about to go looking for a loose electical connection. I'm pretty sure it's not at the battery as I've since stopped and started the engine, so I think it must be on a wire that is not providing current for the starter (or it would'nt start).

Anyone see or hear of this problem before? just to narrow down what I root about for?

edit: as the lights link, it clicks, sounding very much like a relay going in and out.....

Thanks!
Merv.

 

[dxmedia]

Short or bad earth in the binicle ?

 

[TRUKTOR]

I wouldn't necessarily rule out either the Positive
At the battery or the ground at the chassis.
It is an intermittent problem, probably caused with
Something loose, that the jouncing from driving causes
To connect and then disconnect.
The truck could very well start as normal, since it
Is stationary, so, no movement to cause the
Disconnect .
I would start the truck , parked with brakes on in neutral,
And jiggle both the positive and negative leads from the battery
And see if you can induce the problem.
My bet is yes, but, in any event, I'd start there.
Good luck .

 

[DokaTD]

Merv, I had a similar issue. Mine turned out to be a loose alternator mounting bolt which in turn gave me a poor ground on my alt. it was periodic and occurred more as I drove it until I diagnosed and fixed.

 

[mervifwdc]

Well, I've quit for the night, and am 2 steps forward, 1 step back. I ran the engine, and waddled various connections, all right, alternator bolted on solidly. Everything seemed fine. Then I went to drive off, and within 50 feet the warning lights came on solid, and are still on. I've had to park in a town overnight, and am outside the library in "El bolson" to get wifi so I cannot really go ripping things appart till daylight when I can drive to a bit of quiet ground.

I'm hoping that since the lights are now on solidly, it should be easier to track down than an intermittent issue.

Suddenly a strange country where you dont speak the language seems a little more complex to drive through
Cheers.

 

[PAF]

I didn't do a lot of work on my U 1300, so I'm not really familiar with it, but I would try the following :

-the rev counter is fed by the wire connected to the "W" terminal on the alternator. Check that connection
-try to isolate the circuit that generate this condition. I would try and open the circuit breakers one afer the other until the warning lights come off. That would give you a further indication of where to look for trouble
-The clicking sound, if it comes from a relay, could indicate that there is a short (or an open ?) circuit in the circuit controlled by that relay (like a bad light bulb, a grounded horn or sensor, etc. Can you identify the clicking relay ?
-check the obvious : tight connections at the batteries, ground switch, starter, ign switch, light switch, ground connections
-does this condition disappear when the ignition switch is turned off ?
-when it happens, do you see other signs of an electrical problem (dimming lights, headlights, slowing fan, smoke (heavens forbid....)) ?

 

[TRUKTOR]

Another thought - the ignition switch or it's connections.

Since all of the warning lights come on when you turn the key to position 1, before continuing on to Start, I wonder if that " test" circuit is connecting while you are running, whereas it is usually only on with that first Key position.

Since all of your warning lights are on, not just one or two, and since the " test" position
On the key also lights them all up, I would snoop around the ignition switch.
I don't know of another circuit that would be able to light them all up at once.

 

[hammogger]

Mine does that if the alternator belt slips, commonly when it's raining. The tach drops rpm and the DC circuits drop to battery voltage.

The fact that the tach is dropping in rpm says that either your belt is slipping or the alt has a problem because the tach signal does not intermix with the normal DC circuits. DC circuits dropping at the same time says it's not a tach wiring problem.

Bob

Hi Folks,

we hit a new problem today while driving. some of the dash warnings lights blinked on and off, about the same speed as an turn signal. The power also went on and off from the rev counter. It did this about 8 times, then was fine again.

it happened again 20 minutes later.

we've since pulled in (somewhere with wifi!), and I'm about to go looking for a loose electical connection. I'm pretty sure it's not at the battery as I've since stopped and started the engine, so I think it must be on a wire that is not providing current for the starter (or it would'nt start).

Anyone see or hear of this problem before? just to narrow down what I root about for?

edit: as the lights link, it clicks, sounding very much like a relay going in and out.....

Thanks!
Merv.

 

[TRUKTOR]

Bob, I'm just trying to understand -
Do all of your warning lights light up
When your alternator belt slips ?
I can understand that the Charge warning light would
Come on if the alternator is not putting out enough
Juice, but why would all of the warning lights come on,
If they do ?

 

[DokaTD]

I think the brake pad warning lights and one or two others come on if the belt slips or the w terminal is disconnected. But I'm on my bike right now so I can't check.

 

[dxmedia]

Keep it simple. If the whole line of light illuminate and the tachometer dies but everything seems in order is anything shorting in the binicle? Give me one wire with a +ve and I could replicate position 1 on the key.

No point in pulling the truck apart.

 

[hammogger]

Hi Truktor,

You and I interpreted the scenario differently. I was responding that my dash lights dim, and 'un-dim' as the belt slips then catches. That applies only to those lights that were ON to begin with. The effect makes it seem that the lights are turning on and all the way off, but they aren't.

So, specifically, no, my dash lights do not all come on when the alternator voltage drops.

I can't imagine any failure that would cause all dash lights to come on at one time. The OP apparently needs to clarify

Bob

Bob, I'm just trying to understand -
Do all of your warning lights light up
When your alternator belt slips ?
I can understand that the Charge warning light would
Come on if the alternator is not putting out enough
Juice, but why would all of the warning lights come on,
If they do ?

 

[TRUKTOR]

Yes, I think so.
I just re-read the thread, and it says warning lights,
But not every single warning light....
I think if it IS every light, then the position 1 key
Circuit is suspect ....is there anything else that would
Trip all of them, aside from all systems running into
The warning zones at once ?

 

[DokaTD]

Ok, just remembers to check it.

On my truck

If you start the engine then kill it without turning the key you get the following

Two yellow brake wear indicators
Park break indicator (at least I did because I was in park)
The red (brake fluid?) indicator
And finally the batt indicator.

If I still had it, I recall the yellow JR light would come on too.

This I what I see when I turn the key on for the first time. So a loss of the w(tach) terminal will throw most of the dash lights on.

 

[mervifwdc]

Hi Folks,

The morning after I posted this, I drove the truck, and this time some of the lights stayed on (the ones DolkaTD described) and the rev counter worked for a while. This, and the comments in the thread, made me go for the alternator first, and sure enough there was a crappy connector joining wires just before the alternator. I could see the excite wire was just out, so I redid that wire, and off I went, lights working correctly.

but, I later noticed that the batteries were hot, and then checked and I had 30V coming from the alternator. Turns out I had 2 dodgey wires, not 1.

I got that sorted, but it seems to have caused me to loose the turn signals (and the hazard lights) so I guess the turn relay did'nt like 30V. And guess what I cannot find in the town of Esquel, Pategonia?

Many thanks for the help though! It saved me ripping through a lot of stuff, I was originally going to start troubleshooting in the dash. Glad I didnt!

Merv.

 

[mervifwdc]

Well, It seems the relay was indeed fried. And my relay was one of the 12 terminal metal (aluminium covered) ones. It bolts in under the dash, to the left of the steering column, right beside the air vent to the side window demister.

And, as you might imagine, no such think is available in the town where it died.

so: I went through a few motor factor stores, and with one guy who was super helpful, we looked at a number of alternative flasher units. We found one for a Mercedes Bus, and it had 8 terminals and the labeling on most terminals seemed to be the same terminals that my mog was using, but some where just in a different postion on the blocks that had to plug in to the relay.

(Photo of replacement unit)

So, by swaping 1 wire on 1 block, I was up and running. The blocks / location are most easily identified here:

Cost? 220 Argentinian Pesos, or about $50, or just under €40 depending on exchange rates.

If your in argentina and you want one, this is what you need:

No part numbers on it anywhere!

NOTE: There is no K2 or C2 terminal, which means it cannot connect to the second dash warning light for the trailer indicators, so I think it's designed for busses. But it's working great for me.

 

[ALASKAT]

Congrats, to you and the determined Amigo that aided you. Isn't that part of the world boring? Haven't you seen it all on discovery? truly must be amazing, good luck in your travels :surrender:

 

[DokaTD]

So what is that relay for. I had asked about it once with no answers. I to have the aluminum covered one.

 

[ALASKAT]

Flasher relay??? For turn and hazard signals.

 

[TRUKTOR]

Camiones
Omnibus -

Trucks and Buses.
Which ones, who knows?
But that is a good and economical find- might be a good spare to have on board.