I have used them before but my recent experience is not good. They reconditioned an oil and water gauge, whilst I was doing some other, more major work to the car. When that was finished, I found the temperature and fuel gauges over read, which points to voltage stabiliser. Upon checking I found it was giving 11.9 volts, rather than 10. It seems that the Caerbont supplied units suffer from poor quality control and I have since obtained alternatives, that all deliver with 0.05V of 10V.
When one of these was fitted, the fuel gauge was reading a tad under and the temp gauge a lot under. So far, none of my emails, to Speedy Cables, had drawn a response. Eventually, after quite a lot of digging, I found and downloaded some manuals covering Smiths gauges. They set out sizes of resistors required to check the gauges at C,N & H and E, 1/2 & F respectively. My tank is full, so I checked the resistance and it came to 22 ohm. It should be 18 - 20, so if my sender unit had slightly less resistance, the needle would probably go a bit beyond F, as it should when full to the brim (As it is it reads just on F). For now I can live with that.
So far as the temperature gauge is concerned, there are calibration dots on them. At the cold end, a 270ohm resistor is used to earth the sender wire and the needle should be between the two lowest dots. A 68 ohm resistor puts it between the middle dots and an 18ohm resistor puts it between the top dots.
If the needle doesn't line up, as it should, there are two holes, on the back of the gauge, into which a calibration tool is inserted. Without referring to my previous emails, I asked Speedy Cables whether they sold the tools. This time I got a "No" and even when I pointed out that I was simply trying to put right what they had done wrong, the answer was still no but they offered to rectify. I made the tool and did the job myself.
The following email remains unanswered.
I have done it myself. I made the attached tool and read some Smiths calibration instructions that I found online and printed.
I think there were two faults, each of which masked the other. Firstly you didn't calibrate the temperature gauge properly, if at all (It under read) but the Caerbont voltage stabiliser you supplied was giving 11.95 volts, which would offset the error. When I obtained an alternative, that gave 10.02V and connected it to a gauge, that under read, the result was inevitable. I can't quite see why with the Caerbont unit, a correct reading was shown at tickover.
Now that I have familiarised myself with the process, it is obvious that the calibration was way out. When cold, the needle disappeared to the left but given that there are calibration marks, near the C mark, the needle should be near these marks and therefore visible, when the engine is cold. It wasn't something I had concerned myself with before but I have an old photo, of the inside of a Mini I once owned (That used the same gauge) and the needle can be seen in the vicinity of the two cold calibration marks (The engine being off when the photo was taken). By using 270, 68 & 18 ohm resistors, I have now got the needle to line up with the C, N & H calibration marks (The H ones didn't seem too clear but the needle goes up to H when the gauge is connected to earth via an 18 ohm resistor).
One of the bungs, that goes in the calibration holes is missing (Are they important?) and the mounting nut has disappeared into the depths of the dashboard. I may have some spares but if not, are they available as spares?
I don't wish to speculate as to what went wrong with my gauge (Which had been working fine and was only sent to you as it had been removed from the car and it's history was unknown) but it may be worth checking with whoever did the job (If this can be ascertained - invoice 45116) . I also suggest you change voltage stabiliser supplier, as there appears to be a quality control issue with them (Not confined to my experience).
I have since found a stock of nuts and advised them that I simply needed some of the bungs. No reply so far. I rang someone at Caerbont (Which I have since been told is connected to Speedy Cables), asking about the bungs. I didn't mention the aforementioned, as I was unaware that there is a direct connection and someone is supposedly going to get back to me on Monday.
The pictures below show how my gauge was at cold and the needle has disappeared to the left. I had never really paid any attention to this but when I looked into it, it is obvious if the engine is cold or the gauge is switched off, the needle should rest somewhere near in the vicinity of the lowest set of dots. I remembered that I had an old photo of the dash of my second Mini, a 1980 Mini 1000 and when I looked at that, the needle was visible (The engine would have been off when the photo was taken and the oil and fuel gauges confirmed this). The following shows my gauge, before correction and an image of a new gauge taken from the Moss website (The needle position matches that of my old Mini).
I often say that a measure of how good someone is, is how well they act when things go wrong. I don't think Speedy Cables come out of this too well.
Edited by Minor Man, Today, 05:37 PM.
