740 Instrument Cluster Woes

Good day,

I have an 85 740 that just developed an issue with the instrument
cluster warning lights.

After starting the lights remain on as the car is running.

I have not driven the car more than a few feet.

Fuel gage and speedometer have always been flaky

Speedo has been inoperative for some time.

Fuel gage works most of the time and will respond to tap on gage. Now
it's dead. I got as far as checking the connection in the boot/trunk.

Is there a relay or black box that controls the lights?

Does the cluster get ground on the "A" pillar? Near the computer?

I have often suspected the c luster grounds for such things as the
Speedo and fuel gage.

TIA

jimB

 

If your alternator is not charging, the lights will be on. Check the
belt, check the voltage regulator, easiest way to do the latter is put a
volt meter on the battery and see what it reads, then start the engine,
it should be substantially higher, more than 13V. The lights are
controlled by the individual features they monitor rather than by any
one central location, but a charging fault will light them all due to
the design of the system. Same is true of many cars.

 

I am soooo stupid.

I was in a panic for another reason and wasn't thinking right.

Next day what to my surpise do I see sitting in the driveway?

B R O K E N F A N B E L T.

And on top of it, I had the hood open looking right at it!

Some of the panic was my Usenet provider had just dropped the service.

"Car broken... How am I going to get to the Volvo group to get this
fixed?"

thanks James

shamefully
jimB