So again I barely made it home. Majority of my gauge lights came one and i was about to get the car home. Something inline with the exciter wiring is not working. I have replaced the Denso Alternator, added new connector to the exciter wire to the alternator, checked the battery terminals and even soldered all the circuits on the PCB gauge cluster. I have even wiggled the ignition switch behind the key.

After re-installing the gauge cluster into the dash the car worked for a couple days,then stopped working. can someone please help me?

BTW the only gauge that is not working properly is the fuel gauge.

I have no real help to offer- electrons and their habits are a mystery to me, but after reading the posts containing the FAQ quotes I wonder if a circuit fault/intermittent contact on the cluster could be investigated by a swap in of a different cluster. Or perhaps clean all the contacts with a pencil eraser and contact cleaner as a starting point.

If the fuel gauge fault is a recent development try reseating the single female connector on the cluster as that is the one for the fuel gauge.

Good luck,
Randy

I just cleaned every contact and reheated the solder points on the gauge cluster. I am praying that will fix the problem. Thanks for the help guys

Just wondering if i had a bad ground would the gauge cluster still show some effects of the problems i am having... such as when I turn on the key to the second position some lights are bright and the rest stay dim lit even when I start the car.

chris

After cleaning all the contacts and resoldering the Volvo's gauge cluster, it is still not charging. After hooking up all the plugs and turning on the car the idiot lights are dimly lit. However, when I turn on the overdrive button or the parking brake it lights up brighter then the dimly lit ones.

Can someone please help me, I also checked my locate junk yard and they only have a turbo 740 Volvo so I cant take the cluster out of it.

Thanks

Chris

with the key in II position if you ground the red exciter wire the gauge lights should be bright. If this doesn't work then then you have a problem with the exciter circuit in the cluster. If the idoit lights turn on when you ground the exciter wire then the alternator is faulty.

TO further test the alternator you could run a line from the + terminal of the battery to the exciter terminal on the alternator. Start the car and then check the alternator output with a multimeter.

I had a reputable shop rebuild my denso alternator and we could never get it to work. Ended up replacing it with a Bosch unit. Don't assume the alternator is good.
Matt

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'90 245 295k, '93 945 308k

It is worth considering the "rebuilt" alternator isn't working as it should. Unless I misunderstand, problem started when alternator was replaced.

Yes, it's possible re-soldering has messed up cluster, but let's start with alternator details.
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I own a Volvo or Does Volvo Own Me? Try the easy to search Expanded Style FAQ Index http://40mph.com/Brickboard_700-900_FAQ_Expanded_Index_Version/

After cleaning all the contacts and resoldering the Volvo's gauge cluster, it is still not charging. After hooking up all the plugs and turning on the car the idiot lights are dimly lit. However, when I turn on the overdrive button or the parking brake it lights up brighter then the dimly lit ones.

Can someone please help me, I also checked my locate junk yard and they only have a turbo 740 Volvo so I cant take the cluster out of it.

Thanks

Chris

To quote the 700/900 FAQ:

http://www.brickboard.com/FAQ/700-900/ElectricalStarting.htm


Exciter Current Through the Warning Lamp on the Panel. The alternator (charging) warning light in the instrument cluster feeds a small amount of electrical current to the field coils in the alternator when you turn the key on and the engine isn't turning. This excites the coils (electromagnet) and the alternator gets the magnetic field it needs to start charging as soon as the engine runs. When the alternator isn't charging at all (engine stopped) that wire to the alternator also provides a ground path for certain warning bulbs in the cluster, so they light up. Diodes in the network keep current from backfeeding into unwanted circuits. So if you have a bad connection for the alternator warning wire, the alternator won't start charging right away. But most alternators will self-excite once the revs get high enough (say 2000 engine RPM) and then they stay excited and charging, even at idle RPM.

[Editor] To initiate charging upon startup, the small wire going into the rear of the voltage regulator must be at 12 volts. If this is grounded or disconnected (as, for example, through a loose instrument panel or chassis connector), your alternator will not charge. The idiot lights may or may not go on, but if they do and they remain on, then suspect this wire or the panel connector for faults. You can also rarely experience a flexible circuit board failure on the back of the panel. And make sure the alternator warning lamp bulb is not burned out.

[John Randstrom] If you pull the wire off the alternator that comes from the dash board charging lamp and ground it, the idiot light should light with the ignition in the run position. If the lamp does not light then there is a problem with the bulb, the ignition switch, or the wiring/instrument cluster circuit. An easy way to see if this circuit is causing your no charge situation would be to connect a wire from the battery positive terminal through a small spare idiot light bulb(or any bulb with the same wattage and voltage specification) to the idiot lamp circuit connector on the alternator. The alternator should charge and the lamp should light when the engine is off, and go out when the alt. starts charging just like the original dash lamp should do.

[Tip from Paul Golden] I removed my instrument cluster and did the continuity checks, sure enough the solder joints had come loose from the wiring. I fired up the soldering iorn and hit each solder joint with some fresh 50/50 flux core solder. Installed the instument panel and presto, all the lights work once again. Since then I have repaired that same problem in 6 different cars, 760, 3-960, 2-940 so it seems to be a regular problem.

I reponded to your post but for some reason it was posted under the previous threaded post. If that makes any sense at all??

See the post by dan_740 http://www.brickboard.com/RWD/volvo/1587270/740/760/780/zapped_fuel_injection_pump_jetronic_relay_usual_way.html

thanks Art C.
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89-740 GLE;91-940 Sedan ;98-V90 Wagon ___ all running well

How old is battery?

Does ground wire from battery look original, old?
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I own a Volvo or Does Volvo Own Me? Try the easy to search Expanded Style FAQ Index http://40mph.com/Brickboard_700-900_FAQ_Expanded_Index_Version/

the car worked for a couple days,then stopped working

Exactly what do you mean by 'stopped working'? Did it turn over but not start, did the lights dim when the starter is turned, etc.
When it worked, was All well? or any sign of trouble? Any detail is good.


I have replaced the Denso Alternator

With a new one? Rebuilt? Used/good? And its output is what? Has it been tested? Was the old one tested?

The battery is new and I tested that also.

What I meant by working... was after I put the dash gauges back in the car, it charged without any problems and the gauge work. The exciter wire was getting power about 12.1 volt. and the battery was charging about 13.6 volts at idle.

I replaced the alternator with a rebuilt denso one. The reason why I replaced it was it had 312000 miles on it and i could hear the bearing.


I believe the issues is in the gauge cluster plugs or something that has to do with the exciter wire.
I charged the battery this morning and started the car and the exciter wire is not getting any power.