Oil pressure sender mating pigtail or wire terminal?

[PNWMike]

I'm adding a VDO oil pressure gauge to my '06 Ranger 4.0L SOHC and many of the VDO senders have a very handy built in warning light contact that would make it easier and cleaner to do this vs. using a tee and two senders, but I would like to avoid butchering the factory harness to hook up the warning light to the new sender. Does anyone know of a mating connector or pigtail that plugs into the oil pressure switch connector on the engine harness so I could build an adaptor pigtail that connects to the VDO sender?

Alternatively, is there a way to find out what terminal is used in the harness connector for the oil pressure switch? If I knew which one it was, I could find the matching terminal and a connector set that uses those terminals, de-pin the factory connector and proceed that way. It looks like the replacement pigtail for the oil pressure switch is pigtail WPT-439 (Ford part #3U2Z-14S411-MHA), but I can't find any information on what terminal is used in that pigtail.

I am hoping that someone has already solved this and I just haven't found the magic post yet, and if not, that someone with access to more detailed Ford service and technical documentation could look this up.

 

[franklin2]

One of these would not slide right in to the factory wpt-439?

 

[Uncle Gump]

I don't like cutting up the factory harness either. I also wanted to keep the factory low oil pressure warning system as - is from the factory. I chose to use a "sandwich adaptor" at the oil filter to install my oil pressure sending unit... similar to this.

My factory manual does not list a mating connector for the single pin OPS... or a terminal part number. But here is the info that is in there...

 

[PNWMike]

One of these would not slide right in to the factory wpt-439?

I suspect that would be too wide of a terminal and it wouldn't really lock into the connector on the harness or provide any sort of protection from dust and grime. If I can't find the right mating terminal and connector, I'll cut the harness and use a crimp and heatshrink connection for whatever pigtail I use.

I don't like cutting up the factory harness either. I also wanted to keep the factory low oil pressure warning system as - is from the factory. I chose to use a "sandwich adaptor" at the oil filter to install my oil pressure sending unit... similar to this.

Nice! I'm going to try two different approaches, depending on if the VDO sender warning contact is at a compatible PSI to what the OEM ranger's is. The VDO sender is claimed to have a warning contact triggered at 7psi which should be right for the Ranger, but I'll have to try and see. I can run the new wire for the oil pressure gauge in or with the factory harness down to the current sender so it would be nice and tidy.

Ideally the VDO sender's warning light contact is at roughly the same PSI as the OEM sender, in which case I'll just use the VDO sender and let it control both the gauge and the factory idiot light. This case is where I'll either have to find a matching connector or cut and splice the harness. The VDO sender has two identical screw terminals, so I'd likely build a small sub-harness and weatherproof two-position connector to make disconnecting it easier for any future service. I might try and find some push on connectors for the screw terminals, I've seen Ford use them in a variety of places like water temp senders and such.

If the contact in the VDO sender is set at too high of a PSI then the idiot light could end up coming on all the time, which is not helpful if the motor doesn't actually have a low oil pressure problem. In this case I'm going to try and run a small adaptor at the OEM location so I can connect both senders and leave the factory one wired to the OEM connector, like this:

 

[Uncle Gump]

@PNWMike I've used VDO gauges and senders on a couple buggies I've built over the years. I've always used a separate OPS to control an idiot light. I always just figured I would see a big red light quicker then noticing a low reading on a gauge.

That said... I don't believe a sender you describe was available at that time. Does it run the gauge and an idiot light from a single wire? Do you have a link to this gizmo?

 

[PNWMike]

I don't believe a sender you describe was available at that time. Does it run the gauge and an idiot light from a single wire? Do you have a link to this gizmo?

VDO has had senders available with the separate warning light contact in various PSI ratings for years, just not as well known. It uses two connections - one for the gauge and one for the warning light - and uses the threads for the ground just like the OME switch does. Very handy if you can get one with the correct PSI rating and threads, though they are only for VDO gauges. Fortunately, I've always liked the look and function of VDO gauges.

The one I've ordered is https://www.summitracing.com/parts/VDO-360009 - it has a 1/8-27 NPT thread, so is easy to get a bushing to adapt to the slightly larger factory 1/4-18 NPT thread on the 4.0L motor, and the warning light triggers below 7psi, which aligned with what I could find online about the factory switch, and seemed like a plausible PSI for the "oh crap, shut it down NOW" dash light to come on. If you look closely at the sender it has a G stamped into it for the gauge wiring connection and a WK for the warning light connection.

You have to be careful as not all two-wire-connection VDO senders have a warning light contact, some of them have a gauge connection and a gauge ground and don't use the threads for the ground. The more common ones only have one connection for the gauge.

 

[Uncle Gump]

Well I've used that sender a few times. Sold a few through my buggy shop also.

I thought you were saying there was a single wire sender that did both functions. Perhaps I got confused with talk of mating connectors and terminals part numbers.

I would just cut the connector off... crimp on a non insulated ring terminal... heat shrink it and call it a day. I wouldn't be worried about compatibility... it's a switch to ground.

The sender I pictured about is as you describe... 1 signal wire... 1 ground wire.

 

[PNWMike]

Well I've used that sender a few times. Sold a few through my buggy shop also.

I thought you were saying there was a single wire sender that did both functions. Perhaps I got confused with talk of mating connectors and terminals part numbers.

I would just cut the connector off... crimp on a non insulated ring terminal... heat shrink it and call it a day. I wouldn't be worried about compatibility... it's a switch to ground.

The sender I pictured about is as you describe... 1 signal wire... 1 ground wire.

Sorry if I phrased it in a confusing way!

I prefer not to cut and hack the wiring harness if possible, but its looking like I may have to. Bummer. I wish it was easier to get information on Ford terminals and connectors like for GM stuff. Oh well.

 

[franklin2]

Here is a Ford connector/pigtail catalog. But like was said, you want the mate that the pressure sensor itself has, they may not make that. But it might be worth a look.

http://www.fordservicecontent.com/pubs/content/connectors/images/connectorcatalog.pdf

 

[PNWMike]

Here is a Ford connector/pigtail catalog. But like was said, you want the mate that the pressure sensor itself has, they may not make that. But it might be worth a look.

http://www.fordservicecontent.com/pubs/content/connectors/images/connectorcatalog.pdf

Yep, I'm familiar with that catalog, that's how I looked up the info I have. There are a few variants of this PDF out there, but they are all fairly similar.