Strange behavior with oil pressure gauge
10-10-2015, 10:44 PM
#1
Instructor
Thread Starter
Join Date: May 2015
Location: Uganda, Baltimore, PNW, italy
Posts: 218
Likes: 0
Received 11 Likes
on
9 Posts
Strange behavior with oil pressure gauge
OK, just finished installing a new instrument foil in my 1979.
Now, when switching on the ignition, the pressure gauge jumps to full and doesn't move until the ignition is switched off. Then it drops to 0.
Is this normal?
Now, when switching on the ignition, the pressure gauge jumps to full and doesn't move until the ignition is switched off. Then it drops to 0.
Is this normal?
10-11-2015, 01:03 PM
#3
Burning Brakes
Hi,
That is the usual behaviour of the gauge when the wires on the sensor are reversed.
It happened to me when changing the sensor, and reversing the wires solve it.
Regards
That is the usual behaviour of the gauge when the wires on the sensor are reversed.
It happened to me when changing the sensor, and reversing the wires solve it.
Regards
10-11-2015, 09:30 PM
#5
[QUOTE=R.Pires;12662354]Hi,
That is the usual behaviour of the gauge when the wires on the sensor are reversed.
It happened to me when changing the sensor, and reversing the wires solve it.
Exactly....
That is the usual behaviour of the gauge when the wires on the sensor are reversed.
It happened to me when changing the sensor, and reversing the wires solve it.
Exactly....
Trending Topics
10-12-2015, 01:08 PM
#8
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I would remove the wire from the sender and leave the circuit open and see what the gauge does.
Don't see how the wires could be reversed if you just changed out the instrument foil.
Are you sure the foil was the correct for a 79? I'm not sure how many variations there were.
Don't see how the wires could be reversed if you just changed out the instrument foil.
Are you sure the foil was the correct for a 79? I'm not sure how many variations there were.
10-13-2015, 11:43 AM
#9
Instructor
Thread Starter
Join Date: May 2015
Location: Uganda, Baltimore, PNW, italy
Posts: 218
Likes: 0
Received 11 Likes
on
9 Posts
Ok, crawled under the car last night.
The wires were cleaned fairly recently. Came to realize that when I had the alternator replaced in Seattle last fall, the mechanic probably removed the wires from the sender and reconnected them. He may have switched them then.
When I disconnected them, the gauge went to 0 with the ignition on. I didn't have a helper or the time to rig a jumper wire to try grounding either lead to see what happened to the gauge reading.
At this point, I'm assuming the sender is bad.
John,
I overlaid the two foils. They are identical. I've also probed voltages and ground around the oil temp 3 pin connector and the harness. All seems correct. I've also used contact cleaner and stabilizer on the connectors everywhere.
As I have to put the car away for 8 months and head back to Uganda, I'll order one and play with it next summer. I'll play with the wiring at that point.
As a tip to anyone else playing with their foil: the PO bent the contacts on the 3 illumination bulb holders, I assume be wiggling them during removal. I was not comfortable bending them back so they made tight contact with the foil connectors. By placing a piece of electric tape under the foil to raise it for better contact, my dash illumination was stabilized.
Pete
The wires were cleaned fairly recently. Came to realize that when I had the alternator replaced in Seattle last fall, the mechanic probably removed the wires from the sender and reconnected them. He may have switched them then.
When I disconnected them, the gauge went to 0 with the ignition on. I didn't have a helper or the time to rig a jumper wire to try grounding either lead to see what happened to the gauge reading.
At this point, I'm assuming the sender is bad.
John,
I overlaid the two foils. They are identical. I've also probed voltages and ground around the oil temp 3 pin connector and the harness. All seems correct. I've also used contact cleaner and stabilizer on the connectors everywhere.
As I have to put the car away for 8 months and head back to Uganda, I'll order one and play with it next summer. I'll play with the wiring at that point.
As a tip to anyone else playing with their foil: the PO bent the contacts on the 3 illumination bulb holders, I assume be wiggling them during removal. I was not comfortable bending them back so they made tight contact with the foil connectors. By placing a piece of electric tape under the foil to raise it for better contact, my dash illumination was stabilized.
Pete