Do I need to match brands on oil pressure senders and gauges?

belfert · September 17, 2010, 03:03:31 PM

I have a Datcon oil pressure gauge that uses a 33-240 ohm 100 PSI sender. I think the sender is bad.

Do I need to buy a Datcon/Stewart-Warner sender or is there something else I could get like at NAPA? (NAPA would probably have to get from the warehouse.)

I'm not terribly worried if this isn't fixed before I leave on my trip. The DDEC should shut down the engine if the oil pressures drops too low. The rear gauge shows plenty of pressure.

bevans6 · September 17, 2010, 03:37:37 PM

Mostly it's good to match brands. Each one seems to be just a little different. On the other hand, if it works and gives you a consistent reading, use it! It doesn't have to be 100% accurate as long as it's consistent.

Allow me to say I am really glad you are getting it done and going on your trip! Really glad. We are leaving tomorrow for our trip, and the last minute rush is killing me! But it will all be good once we are on the road.

Brian

Mex-Busnut · September 17, 2010, 04:13:38 PM

Belfert is back! Awesome!

oldmansax · September 17, 2010, 05:00:38 PM

Some may work correctly but I have not found them yet. I have a new Steward Warner oil pressure gauge that won't work with the original sender right now.

TOM

belfert · September 17, 2010, 06:00:43 PM

I think the issue is something is reversed somewhere. The sender is probably good although it was doing some strange things last fall.

Background: The original gauge was a Datcon Heavy Duty series gauge. Presumably it was paired with the right sender. I bought a Datcon Illumaseal series gauge to replace it. The new gauge is the same PSI and has the same OHM rating as the original gauge.

The gauge stays at zero when it is off. I noticed this evening when the engine is at idle that the gauge reads 25, but it goes way below zero when I rev the engine. I wonder if I got the wrong gauge or something. I think I will try the old gauge again to see if it works.

I am thinking it is not the sender now. It looks like I couldn't get a sender until Monday anyhow. Could I even install a new sender without getting oil everywhere?

bevans6 · September 18, 2010, 03:52:20 AM

You can normally install a sender without any issue at all as long as the engine is off. with no pressure, the oil stays pretty much where it is -- in the sump!

Brian

oldmansax · September 18, 2010, 08:04:56 AM

Quote from: belfert on September 17, 2010, 06:00:43 PM
I think the issue is something is reversed somewhere. The sender is probably good although it was doing some strange things last fall.

Background: The original gauge was a Datcon Heavy Duty series gauge. Presumably it was paired with the right sender. I bought a Datcon Illumaseal series gauge to replace it. The new gauge is the same PSI and has the same OHM rating as the original gauge.

The gauge stays at zero when it is off. I noticed this evening when the engine is at idle that the gauge reads 25, but it goes way below zero when I rev the engine. I wonder if I got the wrong gauge or something. I think I will try the old gauge again to see if it works.

I am thinking it is not the sender now. It looks like I couldn't get a sender until Monday anyhow. Could I even install a new sender without getting oil everywhere?

You are probably right. The polarity of the gauge is not right for your bus.

TOM

FloridaCliff · September 18, 2010, 12:59:12 PM

Brian,

Any sender with the same ohm range should work.

One of the things I would recommend is to make up a 50' jumper of #18 wire with alligator clips on each end.

Pull the wires off the sender and gauge and hook up the jumper, if it reads the same you can rule out damaged wire between sender and gauge, partial shorts, corroded connection points and move on to checking the gauges ground and the sender etc.

I leave the jumper in my "spare stuff" box and have 50' of spare (emergency) wire if needed.

Cliff

Cary and Don · September 19, 2010, 12:46:26 PM

We had an issue with the datcon gauges and senders. We installed a datcon trans temp gauge and couldn't find the sender so got one from Napa. They won't interchange, even if they are they same Ohms. We ended up contacting datcon and ordered one from them. It seems that even their different models can need different senders.

Don and Cary
GMC4107
Neoplan AN340

belfert · September 21, 2010, 09:51:13 AM

I have determined the sender or wiring is bad. The old gauge does the same thing as the new gauge.

I am leaving at 8 pm tonight so I am just going to run without an oil gauge. The DDEC will kill the engine if no oil pressure. I also will check the rear gauge at stops. It would take a good solid two or three hours to go buy a new sender and replace it.