Unidentified gauge

[Timberwolf]

Just checked the gauge again, it is all electrical, having 3 leads to it, plus the two for the lamp. Logic would indicate that one lead is a common and the two others are for switched sources.

[YC1]

Did you use a voltmeter on it?

[Timberwolf]

From ground to one lead 12 volts, to the other lead 0 volts. Across the two active leads 10.2 volts. No changes after release of parking brake and application of brake.

[stumpnc]

Maybe this will help

[Timberwolf]

Tried direct grounding the two leads coming off the oil filter assembly today, no joy. I've got a full air chassis, the front seems to stay up all the time, the rear goes to sleep. I'm going to search for a sender on one or more of them. Who knows what they did when converting the computer dash to analog? Ah well, I'll just keep chasing and fixing.

[Timberwolf]

It's beginning to look like that's the gauge for my anti-rock system for the coach. I found a reference in the manual today about adjusting the anti-rock in 5 pound increments. I think it referenced up to 80 lbs. too. Now to find the sensor, and the toggle to control it, if that's what it's for. Although I already know it's disconnected, as the air shocks used now have manual fill valves.

[Timberwolf]

I just got a new toy for chasing down wiring. Tomorrow I should know where that gauge originates from!

[stumpnc]

Originally Posted by Timberwolf

I just got a new toy for chasing down wiring. Tomorrow I should know where that gauge originates from!

My guess is a pressure switch somewhere in the brake system. That's my guess.

[guardrail53]

Called a application gauge! My guess too! Wire probably traced to a pressure sensor in the brake system that shows applied pressure! Rail!

[stumpnc]

Originally Posted by guardrail53

Called a application gauge! My guess too! Wire probably traced to a pressure sensor in the brake system that shows applied pressure! Rail!

Yep I have one on my 95 Peterbilt 379 0-150

[Timberwolf]

Well, took long enough, but my back doesn't always cooperate. It was an oil pressure gauge, or I should say- is. However the sensor/sender is toast. Now to find out what it's going to cost.

Thanks for the encouragement!

[YC1]

Originally Posted by Timberwolf

Well, took long enough, but my back doesn't always cooperate. It was an oil pressure gauge, or I should say- is. However the sensor/sender is toast. Now to find out what it's going to cost.

Thanks for the encouragement!

How did you finally determine that?

[Timberwolf]

I was crawling under it to find the endpoint of a braided stainless hose originating from somewhere under the injection pump. It terminated in a junction block with three sensors on it. They all were pressure sensors of some type (appeared to be oil.) So, being as all the connections I'd come across on the rig (underneath and outside at least) were corroded after 30 years I set about removing all wires, cleaning everything and No-Oxing them. While up top I hooked up the fox and hound to the sender lead and took the detector back down with me. The lead on the sender that looked like the one for that particular style VDO gauge (they have a distinctive plastic thumb nut for hold down) had tone.

Might not have found it for a while had I not gone looking for a place to tap into for my boost gauge and wondered where and what for about that line. For some reason (perhaps accessibility?) they were mounted on the frame, readily accessible from underneath. Of course, now I'm wondering what that other pressure sensors are for? One is a ground type for the oil light, but the other?

No shortage of things to track down and repair on this. Oh well, slowly but surely!

[Timberwolf]

As a final note, sensor received and installed. I now have a functional oil pressure gauge,

Thanks to all!