1992 740 Warning lights do not come on

[93Regina]

Disconnect the alternator's belt....and observe.

I say nothing, unless I have a legit schematic.

I was working on a 1996 Ford Escort the other day, and on engine-side fuse box, it showed a "40 amp relay" for injectors, which was incorrect...this relay was for the two-speed fan circuit.

Only by pulling that relay out was the only means to determine Ford mislabel that relay.

Volvo's schematics do not always show the "fine details."

[Eastema]

1992 740 no idiot lights except orange up arrow and seat belt light when key is turned on. Start car and no charging, after 8 minutes or so of driving it will start charging and orange up arrow dims then goes out. Or I can manually flash alternator and it charges immediately. Other times, ( 10% of the time) turn on key and all idiot lights come on, start car and charging properly and no orange up arrow stays on. I have had the cluster out 3 times checking solder points and screw tightness. I have read this could be the problem. It doesn't change anything. Been chasing this for 3 years. Is there a relay that tells all idiot lights to come on when key is turned to on?

[volvolugnut]

Have you inspected the brushes on your alternator? They may be worn short. You should be able to replace the brushes by them selves if you can buy the brushes. The brush holder should be removable with the alternator in place.
volvolugnut

[Eastema]

Yes, replaced couple years ago, as part of my troubleshooting. Made no difference. Gotta figure out what tells all idiot lights to light up when key is turned to on.

[volvolugnut]

Do you have electrical schematic? Remember, the 740 is very much like the 240. If you have a 240 manual it is likely the same.0
volvolugnut

[Eastema]

No, I can't make sense of them anyway. Thanks for trying to help though. Was hoping someone on here had same prob.