Disconnect the battery!

[htiek]

Well, just got through kicking myself!

My oil pressure gauge has recently taken to reading a little higher than usual so thought I would check the sender contacts. After removing the air box for better access I managed to get to the sender and, sure enough, the terminals were a bit on the green, furry side. I have a handy little brass-bristled wire brush which I thought would be the ideal tool to clean them up.

And so it was....right up to the point when it shorted the starter solenoid to the oil pressure sender terminal!

I don't know what current that pulls but it all went to ground through the sender. Perhaps not surprisingly it doesn't work anymore, oil pressure gauge goes to full scale. Grounding the sensor wire puts the gauge to zero so I suspect I now need a new sender. It looks to be a right bitch to get to as well!

Oh well, a lesson learned..working on engine electrics DISCONNECT THE BATTERY

Cheers,

Keith

[TAR]

BRASS - an excellent conductor.

Sorry to hear about your bad experience, but at least you know you will NEVER do that again.

[arbell9]

Keith, you must have gone to the same maintenance and diy school as I did LOL. Feel for you.

[Iconic Ride]

"...DISCONNECT THE BATTERY."

Keith, would you like to hear the story of how I was disconnecting the [boat] battery and ended up "spot welding" my spanner to the terminals?

[molemot]

A friend of mine was servicing the port engine on his 42' Birchwood..he had changed the oil, and was changing the oil filters. He had the filter in his hand when he dislodged the ratchet and socket he was using...it fell across the starter motor terminals and the motor turned over and, being a good Volvo diesel, instantly started!! The oil came out like a fire hose....all over him and the other engine and into the bilges. Sadly, the injector pump is on the opposite side of the port engine, in between the engine and the hull..so inaccessible. The engine was now running happily at some 1000 rpm...so he hauled himself out of the engine room and dashed to the control panel and pushed the "stop" button. This didn't work, as the "ignition" switch was not on, and thus no power to the stop solenoid..so he heaved up the seat cushion, found the keys, tried to turn the "ignition" on, wrong key, ultimately got the right key, turned the "ignition" on and pushed the "STOP" button...and silence fell!!!

So that was the end of several gallons of very expensive oil...fortunately, the engine seemed none the worse for this fiasco and still returns good oil pressure. And all that was with the battery master switch off..as it takes it's supply from the starter terminals which are connected directly to the battery!!

[htiek]

Hi Folks,

Just to close off this thread.

I had a devil of a job finding an alternative sender for my 0-7 Bar oil pressure gauge. Lotus had one but I considered 125.73 GBP a bit expensive. VDO were about 60.00 GBP but unfortunately, after I had placed the order, VDO Germany e-mailed back that the combined 0-7 bar sender with warning light switch was unavailable. A bit of phoning around followed without much success, a few people offered a sender without the light switch but I was hoping for both. A chance comment from Lotusbits took me by surprise though. Apparently Lotus fitted the 0-7 Bar sender to cars with 0-5 gauges and 0-10 bar senders to cars with 0-7 gauges. That seemed odd but looking through the parts list they do sort of look to be grouped that way. Anybody know why?

Anyhow, long story short, 0-10bar opened a few more possibilities so I purchased a VDO 'clone' from ETB instruments 30.10 GBP including VAT and postage. Their technical chap was very helpful and the only spec difference we could find was the low oil light warning on their sender switches at 0.5 bar, I believe Lotus state that the minimum acceptable oil pressure is 0.35 Bar so it may switch on too early.

After dismantling half the engine bay then removing the starter motor for access, I got the old sender out and the ETB jobbie in. Only mod required is to unbolt the smaller spade connector from the old sender and fit it to the warning light connector on the ETB unit (it is supplied with two 'standard' size spade terminals). After getting the car back together I am pleased to report normal oil pressure gauge service has been resumed and no warning lights.

I'll hold off posting it in the 'alternative parts' thread until I'm happy that there's no flickering warning light issues once the oil gets hot, still bloomin freezing up here and didn't get too much of a run today.

Cheers,

Keith

[sanj]

Which sender did you purchase -- the 380 070 250 50, or ??? Thanks.

[htiek]

Hi Sanj,

Yes it was the 380 070 250 50.

24.00 GBP + VAT + Shipping.

Cheers,

Keith