DK55 - Tach and fuel gauge out

curly · Aug 13, 2008

My tach and fuel gauge went out at seeminly the same time. I say seemingly because I just found out about the fuel gauge part as I ran out of deisel yesterday and had to bleed the fuel system. It's still at 1/2 tank even after I added 5 gallons.

Anyone know if the tach and fuel gauge are related...same fuse or anything like that?

Pete Lawrence · Aug 13, 2008

According to the DK55 wiring diagrams (which s**k, by the way) the instrument panel is powered off the "Tail/High, Low Beam" 20 Amp fuse. This includes the Tach, Temp, and Fuel gauges as well as the oil pressure light.

Most other warning lights in the instrument panel return to ground through the panel but aren't powered by this fuse. If the panel warning lights work (Glow Plugs, 4WD, & Parking Brake for example) then the Instrument panel ground connection is probably OK.

Check if you have headlights when the headlight switch is on and low oil pressure light before you start the engine. If so the fuse powering the instrument panel is OK.

There is a 20 pin block connector plus a single wire connector that attaches the instrument panel to the rest of the tractor. It's probably somewhere under the instrument panel. You should check that it's fully seated.

Hope this helps.

curly · Aug 13, 2008

Preciate it Pete. I'll see what I can do with that info.

Pete Lawrence · Aug 14, 2008

I forgot to mention that the manual I have is for the DK55C, although no where is DK55C mentioned, only DK55. Pictures all show the cab version however. Go figure. Don't know if there is a separate manual for the non-cab model. I kind of think there is only one. Anyway, I believe the instrument panel wiring is the same for both cab and non-cab.

curly · Aug 14, 2008

Pete,

I have the Workshop manual DK 501/551 and the Parts manual DK551/DK551C. I'm not really a mechanical person but I was able to figure out how to bleed the fuel system when I ran out of deisel through the manual...but I can't really figure out anything looking at the electrical sections.

No, the headlights aren't working either. And the engine oil lamp doesn't come on when the key is turned. So, does that mean the fuse powering the instrument panel could very well be the culprit? If so, where exactly would I find that fuse

and the fusebox itself? My guess would be to start disassembling the dashboard so I can get up under there and take a look.

I saw on your profile that you are an electrical engineer...dang glad to have you on the forum ny friend

Thanks,
Curly

Pete Lawrence · Aug 14, 2008

Yup, that's the 20 Amp headlight fuse.

The fuse box is under the floor mat near the clutch pedal. Under where your left foot would rest when not on the clutch. On mine there are two cover plates, a small one and a larger one. Fuse box is under the larger one. Access cover is held on with four big screws. Really inconvenient to get to!

Now the question is what caused it to blow. Could have just failed from age or you might have a chafed wire somewhere. First step is to replace the fuse and see what happens. If it pops again you will have to dig deeper into the beast.

I deal mainly with RF communications test equipment, not tractor wiring!

curly · Aug 14, 2008

Pete,

Man, I'm glad I asked. I woulda had started trying to get the whole dash apart. Can't say I ever woulda looked where you said.

I bought the tractor with 360 hrs on it. The fella that sold it to me said since there was no horn, he had installed a horn on it...I'm wondering if that has any effect on it.

No, I didn't think you were a Tractor electrical engineer...but we can hope can't we.

Thanks again

curly · Aug 14, 2008

Pete,

I reckon that horn is causing problems. I put a new fuse in and the oil light came on and the tach was working. Then I pressed the horn button and it blew the fuse.

If I want a horn, I guess I need to try to follow the wires and see if I can see a bare place on metal somewheres, right?

Thanks,
Curly

Pete Lawrence · Aug 14, 2008

Well, if the horn is powered off the headlight fuse then yes, it could be part of your problem. If the new fuse doesn't blow, turn on all the lights and blow the horn. That will tell you if the lighting/instrument circuit is overloaded.

I'll bet he simply ran a wire from the battery for the horn, hopefully with an inline fuse. That would have been the simplest way to do it.

EDIT---

Seems I was typing when you posted your last message. Looks like I loose the bet.

You have to find a better power connection for the horn and/or see what else is messed up with the horn circuit as it's presently wired. As you say "a bare place on metal somewheres."