All is well with my 740 when weather is warm outside. However, if it is cold and I drive with the head lights on, both interior signal indicator lights turn on; no dash, gear shift, lighter lighting works; the tack, speedo, and gas gauge do not work; and I go crazy. I have made repairs to relays in the past, but I have not been able to locate any cracked connections in suspect relays so far. All relays appear warm, but not too hot. Also, after a few minutes (sometimes up to 30-40), again depending on the weather, all of a sudden - everything works. I enjoy this vehicle, but am growing impatient. This vehicle has over 175K and dealer serviceing is out of the question. Any help would be greatly appreciated.

I have the same thing with my 740T, and I go crazy to. Over time the problem has taken less time to go away when warm. If the bill will be a big one, hears a tip. Press the over drive button on the side of the stick. I suppose this triggers the dash to get it's act together and the gauges suddenly fly back to normally. I'm always afraid of getting a speeding ticket because my speedometer reads 140 all the time. Hope you can figure somethin out.

/// Check the alternator belt. Check the voltage as you turn on the lights with the engine running. I have had Volvos that would spit and sputter and not run if the lights were turned on. The problem was the alternator belt. Attempt to turn the alternator by pushing one of the alternator fan blades with your finger (engine off). If you can move the alternator the belt is either too loose, contaminated, worn out. Look around the crank and see if there is oil from a blown front seal. Oil will definitely make the belt slip.

If this is the problem and you cannot get to the repair immediately use brake cleaner to remove the oil, then belt dressing. This is stop gap repair to get you to your next opportunity for repair work. DO NOT GET SPRAY CLEANER IN THE ALTERNATOR !!!

You may have more than one problem and the other posts might be right about the wiring.

notorious for harness insulation breakdown.

Check for bare wires at grounds, ignition coil, etc. If you see insulation is breaking down or missing, the harness will need to be replaced, either by buying a new one or removing the old one and laboriously replacing each wire.

Karl,

If you haven't already, I'd check the headlight and associated grounds. Make sure they are clean and tight.