Waterfoul

I broke the screw out of my original sender so I went to the local marina and got a new one. Does not work. Checked oil pressure with a mechanical gauge. Pressure is fine. Does everything it's supposed to do. Sender shows 70 psi at idle and goes to 25 at anything above 1500 rpm and stays there. So, I tried a sender that Dyno had, gauge stays pegged at 100+ psi when engine is running. Obviously not the right one either. Do I need to get one from Gaffrig??? If so, how do I do this? Website???

blue thunder

When I switched my VDO gages to the gaffrigs I had the same problem. Oil pressure gages read backwards. I had not changed the senders because the place I bought them said they would work with standard merc senders. I figured what I had was a standard merc sender, so all would be ok. Called Nisonger in NY (place where I bought the gages) and they said the voltage reference was obviously backwards. They sent me what they called merc senders which did the trick.

I did note that on the senders that didn't work with the gaffrigs VDO was stamped on the sensing portion of the sensor.

I believe the other sender you tried was shorted to ground... ie bad. If you need the number of Nisonger let me know and I will find it. Otherwise I'll bet bam could fix you up. Last option is, I think I may have a brand new sender you could have free if I can find it.

BT

Waterfoul

Well, the sender I broke is about the size of a walnut. The one I bought is bigger than that, perhaps just a bit smaller than a racket ball. The one I tried from Dyno is smaller than the one I broke. The one I broke (that worked) looks nothing like the other two....it has what, if it were an alternator, looks like a regulator on the end of it. Hard to describe in words.

BT, do you think the one you have laying around (if you can find it) might work with my gauge??

blue thunder

The VDO senders I had (per memory) were about the size of the oil pressure switch, or a walnut and had VDO stamped on them. They did not work with the gaffrigs. I sent those to fishead (from OSO) when he was having trouble with senders, so I have no pics. He sent me back two merc senders, which I did not need at the time. When I pulled my engines over the winter I bent the terminal on one of the senders I was using successfully with the gaffrigs (from nisonger and replaced the VDOs). When I put the engines back in I used one of the merc senders from fishead. It worked fine. Both are about the size of a hackysack. See pic... nisonger sender on left, merc sender on right.

blue thunder

Either of these senders will work with the gages shown in the pic. Say the word and I will send one to you. Any chance what you got from dyno was a pressure switch? That will peg the scale when you turn the key on.

BT

Waterfoul

The one on the right is the one I bought that does NOT work. The one on the left seems a bit smaller, and may be the one I broke that DID work. Only one way to tell.]

Mike Ozinga
1654 Blandford Ave. S.W.
Wyoming, MI 49509

If it works, I owe you a drink if we ever end up in the same place at the same time. If it doesn't work, I'll send it back to you.

timucin

yes!
yes!
yes!

i have serious problems with oil pressures that must be the reason!!!!

Waterfoul

Last season I put my newly assembled motor in my boat and ran it for the first time with my good friend and motor guru Crazyhorse in the co-pilot's seat. The oil temp would spike to over 230 in about 1 minute. Tried all kinds of things to get it under control. Turns out, I had switched the water temp sender and the oil temp sender when I re-assembled the motor. OOPS!! Switched them back and everything went back to normal. Learned a valuable lesson on that one.

Timucin, the senders are VERY important!!!

blue thunder

Waterfoul, both of the senders shown worked on the gaffrigs shown. That says they use the same voltage reference. The senders that I had originally used a opposite polarity, which seems to be what you need. They were sent to fishead. I'll send whatever you want, but I'm thinking this is not the right sender if the one on the right did not work. Do you have a pic of the one that worked? In the mean time I am going to PM fishead to see if he still has the VDO senders. If memory serves me, he does.

Dave

Waterfoul

Dave, well don't send either of those then. The one on the right is the one that does not work. So far, I've tried 3 different senders and none of them has worked. I do not have a digital camera, so I have no picture of the one that worked.