Thanks guys, I just got some really good information on hooking up my new tach setup and the oil pressure gage/sending unit. Turns out AC Delco still makes a very comparable part. Check out my other post ... and thanks for the help.

http://www.chevelles.com/forum/ultimatebb.php/topic/22/4814.html#000001

In the middle of my search, I noticed the advertisements for the repro setups use the idiot light oil/temp sending units ... and I can't figure out how this so.

Either the gauge is set to read "middle" anytime pressure is sensed, and "zero" if pressure is lost ... or it is tied to increase slightly with rpm's.

I see no way to make my current open/close switch to read a variable output? So what's the story guys, are these repro setups really that generic ... Or, is there a means to retrofit my existing pressure switch?

Thanks, Neal

ttt

Trying to figure out if there is some way I can use my idiot light sending unit temporarily to run the gauge?

I don't think so, but somehow the aftermarket is doing it.

Thanks, Neal

Come on, anybody got a response ... I was sure some of you had installed the aftermarket one's before.

How in the world are they using a stock oil pressure and water temp sending unit that is only designed to be on/off? I really don't get it?

Thanks, Neal

Not sure what you are asking.

Are you saying that you think someone is using idiot light type oil pressure and temperature sending units to operate gauges?

If so, who is doing this?

I appologize, maybe I wasn't asking right.

I did recently pick up an original tach/gauge cluster. In doing the research, I found that AC Delco still makes a service replacement oil sending unit #15591103. I actually found it on www.acdelco.com, (http://www.acdelco.com,) minutes before it was posted on Chevelle Tech question. Thanks guys, I'm sure I'm not the only one looking.

While I was also looking for that, I discovered that the conversion unit OPG is selling is advertised as using the original harness and original sending units.
https://www.opgi.com/product.asp?ProdCode=CH24771&topcatid=14&grpcode=27230&yearrange=&chapterid=701

I presume that all these conversion gauge kits are the same, as there can't be many people making this thing for that price.

The harness I can kind of accept, though I think NoNeck's approach is the most thought out.

The original sending units I am having a hard time with ... but if they can do it, evidently I can too. Personally I don't believe any gauge is capable of working properly with a non-variable on/off control.

So, the question is ...
1) Is it even possible to make a gauge operate correctly with the original idiot-light senders?

2) If they are doing it, why can't I ... and how?

Thanks again for any information ... if it's possible it's saving me $50-70 for new sending units.

Neal