I have a 1990 Volvo 760 with the 4cyl Turbo. It has a 175k miles on it.
I have gone thru 2 alternators in the last year. Every two weeks the car's alternator stops working and causing it to drain the battery. Eventually the car will just die while driving it and not start (No turning/Clicking). After waiting about 20 min it will start but hesistant to do so.

I made the mistake of taking it to Carx who doesnt seemed to know what they are doing and may think it may be something simple they are overlooking. They seem to think its in the dashboard wiring that is grounding out the alternator. They believe this because when it starts draining the battery none of the dashboard lights come on when starting the car. I am not sure what they so to make it run for two weeks but this has been going on for 2 months. I will probally just take it to a Volvo dealer to get fixed but would like to have an idea what it is so I might try and fix it myself.

Thanks in advance for your help!

 

Look at the circuit board on the back of the speedo cluster for breaks.

 

Thanks Tech,

I took it to an all Volvo mechanic shop and came to the same conclusion. $300 for part/labor which is a fair price to me.

I just hope this does the trick. My wife loves this car so much that she turned down a new S60 and rather drive this one.

 

Hi

My '88 760 turbo experiencing the same problem as axis72's and would like to understand it better. My Haynes manual depicts a voltage stabilizer in the instrument cluster but does not mention anything about it in text. Does it have to do with that item? I'd love a brief explanation of the problem.

As a side note, the manual stops interior disassembly procedure at '84, so the proper order of center console and dashboard disassembly is a bit gray to me. It is made worse by the last hack who did a horrible job on it. Recommendations for a good shop grade manual for this vehicle would be appreciated.

 

A few causes here.

1) Bad signal from instrument cluster circuit board.

2) Bad voltage regulator.

3) Bad vibration damper on main pulleys.

Mine was the last. The shop I got my replacement from had three examples in the shop when I picked mine up. The rubber damper splits from the pulley and as soon as any load is put on the accessory belt, like the AC or alternator load, it stops spinning.

 

The last can be guessed by the power steering not working so well and the AC compresser failure warning (flashing light on AC button) coming on.