"Marine" sending units special?

[fogducker III]

Doing a rebuild on my 1997 454 Mag MPI and going to replace all the sending units, can I just use automotive application ones?

We all know some auto parts are interchangable and MUCH cheaper but I am not 100% with the sending units....?

There are two water temps, one oil pressure and one oil "switch" and the "knock" sensor......I figure if I go to the auto parts store and ask for these for a 1997 454 Vortec Suburban it will save some $$$

Or am I thinking out my a$$....?

PS. After paying for an IAC unit from Merc I feel violated.......http://www.donzi.net/forums/images/smilies/Annoyed.gif

[gcarter]

I think temp and pressure units will work fine, maybe not for knock sensors, but then I don't know.

[fogducker III]

I think temp and pressure units will work fine, maybe not for knock sensors, but then I don't know.

Thanks George, I was leaning that way also.....personally I don't even know what the knock sensor does.....:bonk:

[yeller]

Water temp YES......oil pressure NO. At least not with the Faria gauges I had in my 16. I can't remember which is which, but one sensor controls the negative side of the gauge and the other controls the positive side of the gauge.

I.e: One type will have a voltage on the sensor....not sure if it's a full 12volts...never measured it. The other type doesn't. Basically the sensor has a grounding wire attached to it.

[axelkloehn]

Water temp YES......oil pressure NO. At least not with the Faria gauges I had in my 16. I can't remember which is which, but one sensor controls the negative side of the gauge and the other controls the positive side of the gauge.

I.e: One type will have a voltage on the sensor....not sure if it's a full 12volts...never measured it. The other type doesn't. Basically the sensor has a grounding wire attached to it.

yep, had the same experience with my automotive oil pressure gauge, the marine sensor is different, so my gauge did not work properly and quit its job with some smoke after 3 hours driving!

[gcarter]

Water temp YES......oil pressure NO. At least not with the Faria gauges I had in my 16. I can't remember which is which, but one sensor controls the negative side of the gauge and the other controls the positive side of the gauge.

I.e: One type will have a voltage on the sensor....not sure if it's a full 12volts...never measured it. The other type doesn't. Basically the sensor has a grounding wire attached to it.

Autometer gauges (Autometer and Livorsi) might be different.
I'm sure you could ask or email Livorsi.

[gcarter]

Thanks George, I was leaning that way also.....personally I don't even know what the knock sensor does.....:bonk:

Thunderbolt V ignition?
The knock sensor notes detonation in the engine and sends a signal to the module on the distributor to retard the spark advance to stop the problem and any resultant damage.

[mrfixxall]

it depends on who's gauges you have,gaffrig and livoursi use special sending units for their stuff..

[fogducker III]

Thank you gentleman, as usual, great info.....:)

I have a new set of Hardin Marine gauges, they replaced the stock VDO gauges, no sensors changed at that time....I guess just to be safe I bite the bullet and order the Merc units......:frown: (other then the water temp...)

PS. Yeller I need my leg stand vacated......:wink: