Oil pressure gauge issue

[mstoelton]

1999 5.0L Mercruiser in a chap 220 LE

No oil pressure on gauge

changed gauge, changed sender unit

No oil alarm going off so I believe it has pressure.

What do I do next to trouble shoot pressure gauge/sender?

 

[Bt Doctur]

Re: Oil pressure gauge issue

first you make sure it has pressure by installing a mechanical gauge,
Check oil gauge at dash for 12v with the key "on", then ground sender wire at engine. gauge moves =wire good. no movement= wire open

 

[mstoelton]

Re: Oil pressure gauge issue

first you make sure it has pressure by installing a mechanical gauge,
Check oil gauge at dash for 12v with the key "on", then ground sender wire at engine. gauge moves =wire good. no movement= wire open

How do I install mechanical gauge?

 

[Bt Doctur]

Re: Oil pressure gauge issue

there usually the same thread as the sender. remove the sender and thread in the mech gauge.depending on your exact setup, you may need short nipples coupler fittings to extend up/away/sideways to make the connection.

 

[mstoelton]

Re: Oil pressure gauge issue

there usually the same thread as the sender. remove the sender and thread in the mech gauge.depending on your exact setup, you may need short nipples coupler fittings to extend up/away/sideways to make the connection.

Installed mechanical gauge, have oil pressure.

Grounded wire to block with key on - no response.

Ran jumper wire from sender to light blue wire on gauge bingo, sender wire is open.

Ran new sender wire. Sender now showing oil pressure. System is now functional. Permanently mounting mechanical gauge in engine compartment as a 2nd check.

Thank you for the help BT Doctur.