If a 88 Chevy Pickup Truck seems to be low on power the timing should be checked. The fuel pressure and fuel pump should also be checked and may be the source of low power in the vehicle.
Low power steering fluid or you need a lube job.
The LOW pressure fitting is SMALLER than the HIGH pressure fitting.
Low coolant
One of the causes for low oil pressure in a Chevy Tahoe could be a clogged or dirty oil filter. Changing the filter may get rid of the problem.
I think it is on the accumulator/receiver dryer.
Disconnect the low pressure line
Low coolant, bad thermostat, clogged radiator, bad waterpump, bad headgasket, etc
not downshifting.
on the passenger side close to the firewall on the receiver dryer
That would be the low pressure service port and it should be located on the receiver/dryer.
just use a light tester, clamp the gator clamp on a ground turn your light on and jam the tip into differant wires on the plug, you will actually have 2 power wires, one for low beams and 1 for high beams
The power steering is electric.....a motor runs it.