Lotus Elan and Lotus Elan Plus 2 Forums

I have an Elan+2 1968 - the spartan model - that has been modified to neg earth and alternator. Temp- and Fuel instruments have started to show wrong values and I suspect the Voltage Stabilizer.
- What is the right way of checking that the stabilizer is OK? Measure volts in and out on just the stabilizer, or should instruments be connected when measuring voltage? Is a slow pulsation between 11.5 and 7 volts OK or should it be a steady 10 volts?
- The original stablizer was equipped with a double connection marked "B" and one single connection marked "E" or "F" or "P" (not very easy to read) and one double connection. Between the single and double connection "E"? is a small condenser fitted.
Voltage to instruments was from "B" and to the stabilizer from ignition was to the single connection and out to "+" on the rev.counter was from the double connection. I guess this arrangement with the condenser is to supress disturbance to the instrument or the radio?

Grateful for advice

Jan

The terminals are
E earth
I instruments
B battery

Alan.

I, too, have a similar problem. Water temp and fuel gauge with low readings. I suspected the same issue but have had a heck of time trying to locate the voltage stabiliser. Mine is a '69 two fuse model. Anyone know where the SOB lives in the early +2's.

Regards.

Greg

My 1969 Elan +2 federal LHD, neg ground had the voltage regulator screwed to the backside of the dash board. If memory is correct to the left of the speedo and tach.

It may be secured on a threaded stud attached to the speedo or tach.

Bob
1969 Lotus Elan +2
1968 TVR Vixen
1963 Jaguar MK2

Same location as Bob for mine. I replaced it with a solid state modern replacement and did not bother with the suppression capacitor. All works well. It delivers a steady 10v dc output, instruments connected or not connected. They are readily available from Moss or other suppliers.

I believe some of them have an earth connection and some need the body grounded. Also note the original vibrating one's have to be installed right side up. I assume they would have a 10v output as well, but never checked the original.

HTH

Thank you all for your answers - especially Alan with picture and really clear instructions!
Now I have got it right - my stabilizer was mounted on the oil pressure instrument and thus difficult to get at. Will be on speedo from now on.

Jan

Hi. I may be a bit late with this reply but I've not posted for a couple of weeks so thought I'd launch in anyway - just completed a house move - we've got a lot of stuff! The elan is now tucked away in its new garage - hopefully not staying there for another 10 years.

Anyway, the stabiliser has a bi-metallic strip inside that heats up, opens, then closes again several times per second. The higher the voltage the higher the heat up rate and the switch stays open for a larger proportion of the time. So, seeing a pulsating voltage is correct. The guages connected to the stab are also using a bi-metallic strip, so the pulsating doesn't matter - the average voltage should be about 10V.

Hope that helps - a PDF explaining how the stab works has been posted on here before if you're interested.

All the best.

Sean.

Hi All,
You can of course rip the bi metalic strip out of the housing and replace with a solid state +10V regulator. Much more relaible and will last forever ( well, nearly).

Kind regards
Jeff 72+2

stugilmour wrote:Same location as Bob for mine. I replaced it with a solid state modern replacement and did not bother with the suppression capacitor. All works well. It delivers a steady 10v dc output, instruments connected or not connected. They are readily available from Moss or other suppliers.

I believe some of them have an earth connection and some need the body grounded. Also note the original vibrating one's have to be installed right side up. I assume they would have a 10v output as well, but never checked the original.

HTH

Moss Motors, ltd has a nice troubleshooting guide on their voltage stabilizer description for part 131-555. Thanks for the location of the unit on your cars. I was looking all over. You definitely narrowed it down.
Cheers,
Greg