Fred Werring
Well-known Member
It was a combination of things. The oil pressure switch was bad, it stayed open even with no pressure, it got replaced.
The light itself was intermittent (probably when I was playing with it). Removed the bulb holder, bent the little prongs up a bit. Took a cotton swab doused with plastic safe contact cleaner to clean up the printed circuit board, didn't have to remove it.
Cleaned up the rest of the lights, they only ones that don't work now are the diff lock and parking brake...I can live with that.
Thanks
Fred
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Original message
Noticed the oil pressure warning light wasn't working on my 398, wasn't lighting up with the key on engine not running.
Did find the oil pressure switch was open (no continuity) with the engine off, assuming it should be closed. Got another one coming.
tried grounding the wire going to the switch, had a good ground, light still didn't come on. Checked the bulb with a meter, swapped bulbs, still nothing.
The shop manual I have (yes, ebay) is a little vague when it comes to the instrument panel. Assuming it's like most oil pressure idiot lights...+12v to the light, wire to the pressure switch that completes the circuit. Right?
And anybody got a generic replacement for those little warning light bulbs? Only thing I've found online is from Massey, $6.95 each plus shipping.
Thanks
Fred
Hi Fred,
I actually have the instrument panel removed from a customer's 390 at this moment. The fault is intermittent working and dim warning lights.
There are several possibilities for this. Firstly the bulb has failed. Secondly the little tags on the bulb holder are broken and the holder contacts are not making contact with the copper ribbons and thirdly the terminal plug is either not fully engaged or the contact terminals are dirty. The long block connector did not appear to be fully engaged when this one was removed. Inspection showed that the terminals on both connectors were dirty as well as the main instrumentation connector.
This instrument panel is a bit of a pain in the proverbial to remove especially the two M6 nuts at the top. Fortunately the connections can be attached before the panel is refitted to test the lights.
The small bulb holders can be supplied from MF with bulbs at an expensive ?8.82 ($12.17 today) or the bulbs are available seperately as you have found out. I have replaced 6 small holders on this panel. Holders are not available on their own from MF.
To further test the oil pressure circuit you can replace the 'oil' bulb with one from a different function.
DavidP, South Wales.
The light itself was intermittent (probably when I was playing with it). Removed the bulb holder, bent the little prongs up a bit. Took a cotton swab doused with plastic safe contact cleaner to clean up the printed circuit board, didn't have to remove it.
Cleaned up the rest of the lights, they only ones that don't work now are the diff lock and parking brake...I can live with that.
Thanks
Fred
-------------------------------------------------------------------
Original message
Noticed the oil pressure warning light wasn't working on my 398, wasn't lighting up with the key on engine not running.
Did find the oil pressure switch was open (no continuity) with the engine off, assuming it should be closed. Got another one coming.
tried grounding the wire going to the switch, had a good ground, light still didn't come on. Checked the bulb with a meter, swapped bulbs, still nothing.
The shop manual I have (yes, ebay) is a little vague when it comes to the instrument panel. Assuming it's like most oil pressure idiot lights...+12v to the light, wire to the pressure switch that completes the circuit. Right?
And anybody got a generic replacement for those little warning light bulbs? Only thing I've found online is from Massey, $6.95 each plus shipping.
Thanks
Fred
Hi Fred,
I actually have the instrument panel removed from a customer's 390 at this moment. The fault is intermittent working and dim warning lights.
There are several possibilities for this. Firstly the bulb has failed. Secondly the little tags on the bulb holder are broken and the holder contacts are not making contact with the copper ribbons and thirdly the terminal plug is either not fully engaged or the contact terminals are dirty. The long block connector did not appear to be fully engaged when this one was removed. Inspection showed that the terminals on both connectors were dirty as well as the main instrumentation connector.
This instrument panel is a bit of a pain in the proverbial to remove especially the two M6 nuts at the top. Fortunately the connections can be attached before the panel is refitted to test the lights.
The small bulb holders can be supplied from MF with bulbs at an expensive ?8.82 ($12.17 today) or the bulbs are available seperately as you have found out. I have replaced 6 small holders on this panel. Holders are not available on their own from MF.
To further test the oil pressure circuit you can replace the 'oil' bulb with one from a different function.
DavidP, South Wales.
