Everyone,

I recently swapped in a relatively low mileage stock "ribbon" style cluster into my '70 145 and I am having a strange problem. Periodically, typically when I come to a stop, the fuel and temp gauges will stop working and peg to the right (i.e. "full" and "hot"). Also, I haven't been able to confirm, but I believe the dash illumination also goes when this happens...however, once driving a bit the gauges come back to life. I have gotten under the dash and see no issue with the wiring...I am beginning to suspect it is maybe a bad 5v regulator but I am not sure how to test it. Any one had similar issues? Any methods for testing the 5v regulator (or where to source a replacement)?

Thanks!
Brian

Gas will read low and temperature will read high if the 67-72 voltage stabilizer is bad.
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71-145-S ; 82 245GLT ; 72-1800-ES

When dealing with low voltage circuits there are three points to remember,Earths, Earths, Earths.

Seemed to be a ground issue...I added a ground strap and new the gauges appear stable...no pegging incidents so far. A good cleaning of the connections seems like it is also in order.

Brian

5 Volt regulator? What uses 5 volt. I think the regulator, actually a voltage stabiliser is 10 volt. That takes the instruments out of the up and down range of the alternator.
Check that your fuses are clean and tight.

5.1 volts according to my Volvo green book.

However, I think starting in 1973 the 140/164 and all of the 240/1640 use a 10 volt stabilizer.
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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502

Thanks Erik. Very odd, seems to defy logic. 1970 green book has it at 5.1v and 1973 shows 10v.

well the whole dash, gauges and more went to 240 specs in 73 so the voltage difference cant come into play unless you swap a 72 and below dash in?

Clean all the connections and I bet you'll be ok.

If not, I've got a voltage stabilizer that may work.
(I don't think that's the issue though.)

Make Sure nuts on all terminals are snug,make sure dash is earthed or gauges may burn out. others can advise if unit has earth strap.