Hitting highs and lows today. Really up when I found a small VDO tach for my '91 automatic 245 at a salvage yard. Tach has three terminals on the back (+, -, and Gnd), plus the light. Installed tach per some of the groups previous instructions with the white and red signal wire going to + and a ground installed to -. Even wired the light. Upon first engine start the tach went to about 2,000, then jumped to 4,000, then swung hard right and pegged solid against the stop. Now all it does on engine start is immediately peg on the high side and stays there like glue. At least the light works. Have tried different position of ground wire to third tach terminal marked "Gnd", tach doesn't move with ground at this position. Suspect tach is bad, would appreciate any ideas before I look for another tach in case I have accidentally fried this one with my wiring.

Thanks!

Mike

just a suggestion. Why not get a big tach and the small clock? I think this looks much better, and the gauges are much more common. The small tach was not a very common accesory. I don't think it was standard on any model. I have actually never seen a small tach.

On most of the 52mm accesory gauges:

G = sender. For tach, oil pressure, oil temp, ambient temp, etc, this terminal gets the signal from the sender (or with the tach, from the coil).

T = ground. (it's more like an upside down "T") Lots of screws behind the center console can be used for a ground connection, but I think you got this one already.

+ = 12V power. You need to run a wire from the fuse panel to the gauge, and it should be on when the key is in the "II" position (run). I forgot which fuse I used for my gauges, but I could check if you want to know.

I use 16 gauge wire for all of mine, but I'm pretty sure the Volvo original was 18 gauge (thinner). One trick I've done is to cut a piece of wire about 3-4" long, twist it together with the wire that provides the gauge with power and crimp it into the same connector. Plug that into the "+" terminal and then put a connector on the other end of the short wire, and now you can connect that to one of the light bulb terminals and really cut down on the number of wires needed. Do the same with the ground.

And if you have another black spot to fill, I've got an ambient temp gauge for sale on ebay - Item # 601428492
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Michael -- 1987 244 GT | Volvo 240 Links

Rewired the tach as you as you suggested, application of 12v to + terminal immediately pegs the needle and signal to G terminal makes no difference. Suspect the gauge is bad. Thanks for the help!

Mike

p.s. Now if only you had an oil pressure gauge instead of ambient temp ...

Too bad about the tach. I had one for a while that I found at a junkyard, but I sold it. The car I got it from was an '82 244 DL w/B21F, and the tach had a 6500rpm red line (I've never seen a 6K variation from a B23F/B230F). The only reason I had a shot at getting the gauge was because the car was wedged against another car on the drivers side, and the front end was up in the air with the engine removed. I guess no one else wanted to climb through the passengers side just for a gauge!

I've got a spare 5 bar oil pressure gauge if you're interested. It's the one that came in the 240 Turbo, and it has "Volvo" on the face. $12 plus shipping. Let me know if you want it. I have no way to test it so I can only assume that the ones I have are good. If it's not, I'll take it back and issue a refund less shipping. I've got an extra Volvo volt gauge too if you're interested.

thanks.
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Michael -- 1987 244 GT | Volvo 240 Links

Gnd terminal is not ground. G terminal is gauge or some such in german. That is where the red/white signal wire attaches. = is positive switched hot, - is ground to any ground on the car.
Bill D.

Thanks, Bill. Changed the wiring as you suggested, tach still pegs with application of 12v to + terminal, input signal to G terminal makes no change. Suspect the gauge is bad. Mike