Oil pressure sender

[vtullomk4]

I ran the Speedhut oil pressure sender from the block direct to the gauge. I see forum posts that it needs to be grounded. If so, do I open the cable to ground? Thanks for the help.

Vince

[edwardb]

No, you shouldn't have to break into the Speedhut provided cable from the sender. The gauge has a separate ground wire and should be all you need.

[vtullomk4]

I tried cranking engine, but oil pressure pegged at zero. Attached is the connection diagram. Does the ground for the lighting ground the sensor? So I used Teflon tape. Do I need to change to Teflon paste?

148391

[edwardb]

You may/may not get enough oil pressure to move the needle with just cranking the engine. That ground wire in the diagram isn't just for the lighting circuit. It's also the power for the gauge and all it should need. If you needed a separate ground wire for the cable (e.g. a breakout as your original question) Speedhut would have shown it. They are quite thorough in their instructions. Since the sender is grounded through the harness, sealant on the threads doesn't matter. I personally don't like tape, but that's a separate issue. As long as it's not leaking you're OK. The instructions are for a 3-wire sender. The newest version, which is good. I assume the needle goes to zero when you turn the key on? If so, pretty good chance it's wired properly.

[Jeff Kleiner]

If you're using the RF harness and FFR switch it drops out the gauge power (and most everything else except fuel pump and ignition) while cranking therefore you won't see pressure.

Jeff

[vtullomk4]

Thanks edwardb and Jeff. For this gauge I am not using RF harness. I am using Jeff’s hybrid setup. Cable direct from oil pressure sensor to gauge. Just putting key to on and then just cranking with no plugs and no gas to check wiring, dash etc I’ll get gas in for first start and see if it registers.

[rich grsc]

Do the gauges sweep when you power on?

[vtullomk4]

Got it sorted today. Edwardb was correct. Cranking does not move the gauge. I was able to do first start, and pressure is fine. All gauges read accurate. One curve ball. I never realized the water temp gauge was centigrade. I thought it was reading wrong, but converting to F resulted in 190. I’ll post the first start.

Thanks to all for the help.

[edwardb]

Got it sorted today. Edwardb was correct. Cranking does not move the gauge. I was able to do first start, and pressure is fine. All gauges read accurate. One curve ball. I never realized the water temp gauge was centigrade. I thought it was reading wrong, but converting to F resulted in 190. I’ll post the first start.

Thanks to all for the help.

Congrats on the first start. What I said is typically the case. But as Jeff also pointed out, the gauges are powered by the ACC FED portion of the Ron Francis harness (if that's what you have) which is shut off by the ignition switch when in the start position. A small detail I forgot about. So that's another reason you wouldn't have seen an indication when cranking. Glad it worked out.