Speed PHreak

Ok, heres the deal I've got 3 guages, a mech. water temp, an electiric oil pressure and an A/F guage. I have the power supplied to all by a single wire, same goes for the gound.

Well heres the deal. I have the oil sending unit and the stock oil pressure unit removed from the block and hung under the intake manifold via a peice of braided SS line. Now when ever I turn on the car the O/P gauge wiggles a bit but doesn't show any real reading when the car is running. However, if I disconect the ground from the guage, it reads around 10~15 PSI when the car is running!? Now if this is correct(which I doubt) I dunno why I have to dissconnect the ground to get any reading out of the guage.

It occured to me that prehaps the sending unit is being only partially grounded and if it were totally grounded the sending unit would read right. Am I correct? I have the sending unit held up by plastic tie wraps and one of those OEM wire haress clips. Perhaps I should get some sort of metal to metal contact going........

preplexed

~steven

sgT

the sender must have a ground.

Speed PHreak

Even if you have the sender that doesn't have grounding terminal?

sgT

the grounding terminal is the sender itself.

it is expected that the sender be mounted in the engine which is a ground source