I have absolutely hit a wall with my 940 brick! Please help me...
When my SRS dashlight goes on my charging system doesn't "charge". When the SRS light goes off my car works and "charges" just fine. Through several mechanics and personal trials; replacing the alternator does not fix the problem. Regardless of the old alternator or a replacement I get the same result.
If the SRS light stays on my 940 behaves like there is a bad alternator. After I allow the mechanic to install a new alternator it still will not charge. The old alterantor then has a positive bench test and proves not faulty. The mechanic then looses an easy payday but tries to regain losses and insists its the battery.
The battery is less then a year old and passes every test. Plus I have a 3 year warranty on the battery so they can't sell me a battery. I also have personally replaced the alternator 3 times myself. It takes a 13mm to loosen the tensioner, a 12mm and 13mm to remove the mounting bolt, and a 13mm and 8mm to remove the leads.
Here is my confusion/dedication...I have proved to myself that my charging system works when the SRS light is off. While the SRS light is on regardless of a new battery and alternator or an combonation of the two. While the SRS light is on my 940 doesnt charge.
I have the 100 amp alternator. I believe the voltage regulator is built into the alernator. This problem is intermitten and makes me believe the charging system is fine. The SRS light has a mind of its' own regardless of components.
I love my 940 brick and want to fix her. I am at a point finacially to either get a "push-pull-or-drag-it-in" value for a trade in. Plus my beloved brick gets crushed and scrapped. I will loose sleep over it (possibly cry into my cereal)!
After reading the discussion boards there is a contact or wiring problem that has an easy fix which doesnt require a dealership visit...your help is greatly appreciated!
Thanks,
shadydave007
Help Me Save My 940!
Started by
Guest_Shadydave007_*
, Oct 30 2010 11:17 PM
7 replies to this topic
#2
Q-Ship
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Posted 30 October 2010 - 11:40 PM
bummer, sorry.
I don't know of a specific fix, but I would check the ground. In fact, I would add a heavy duty ground to the chassis. About 80% of the electrical problems I've had in various cars could be traced to ground problems. I'd start there until someone chimes in with a specific answer.
I don't know of a specific fix, but I would check the ground. In fact, I would add a heavy duty ground to the chassis. About 80% of the electrical problems I've had in various cars could be traced to ground problems. I'd start there until someone chimes in with a specific answer.
'96 855 automatic. Color 214 <-now I will remember this. IPD stage 1 ecu, rip.
#3
Q-Ship
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Posted 30 October 2010 - 11:55 PM
er, please be careful with this, but there is an SRS ground beneath the driver's seat next to the crash sensor. Disconnect the battery negative and wait some time for any charge to dissipate from the crash sensor and check the ground there?
'96 855 automatic. Color 214 <-now I will remember this. IPD stage 1 ecu, rip.
#4
Three Fat Tigers
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Posted 04 November 2010 - 01:23 AM
That's funny, my '94 940 just started doing the exact same thing a few days ago. Though when this happens the idiot lights don't turn on with key, but the SRS light stays on until I rev the engine high enough (3.5 to 4k rpm) to auto-excite the alternator where it starts charging. Normally power passing through the charge failure light continues through the small red wire at the alternator to provide the power necessary to generate the initial magnetic field in the alternator so it can start charging immediately. The charge idiot light grounds out through this red wire, and so it lights up, but after the alternator is charging, the lamp sees 12V+ on both legs and so it turns off. The other idiot lights also ground out through this red wire via diodes which act to allow them to only see the ground and prevent them from seeing the 12V+ after it's charging.
Haven't yet had a chance to investigate the issue on my car, and it has fixed itself for the moment. I believe the fault is in the instrument panel, shouldn't be too difficult to track down.
I would inspect the small red wire at the alternator and make sure it looks in good order. You might disconnect this wire from the alternator and jumper this to a ground, with the ignition on the idiot lights should turn on, but if not, next inspect the instrument panel and it's connectors. I'd be more specific as the which connector but I don't have access right now to my manuals. Might be a fault in the flexible printed circuit board on the backside of the panel, which could be a visible fault, or may require tracing it out with a multi-meter.
Haven't yet had a chance to investigate the issue on my car, and it has fixed itself for the moment. I believe the fault is in the instrument panel, shouldn't be too difficult to track down.
I would inspect the small red wire at the alternator and make sure it looks in good order. You might disconnect this wire from the alternator and jumper this to a ground, with the ignition on the idiot lights should turn on, but if not, next inspect the instrument panel and it's connectors. I'd be more specific as the which connector but I don't have access right now to my manuals. Might be a fault in the flexible printed circuit board on the backside of the panel, which could be a visible fault, or may require tracing it out with a multi-meter.
#5
vivalavolvo
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Posted 21 December 2010 - 01:52 PM
I would inspect the small red wire at the alternator and make sure it looks in good order. You might disconnect this wire from the alternator and jumper this to a ground, with the ignition on the idiot lights should turn on, but if not, next inspect the instrument panel and it's connectors. I'd be more specific as the which connector but I don't have access right now to my manuals. Might be a fault in the flexible printed circuit board on the backside of the panel, which could be a visible fault, or may require tracing it out with a multi-meter.
Following that, Make sure the bulb in the dash is good. The current passes thru this bulb to excite the regulator and if its bad/loose/missing you will not get a charge. The reason the SRS light comes on is because the voltage is to low for it to operate, so it shuts down and puts on the warning light.
1978 242DL - 1995 855 T5 ARD Green - 1991 Stanza XE
#6
Three Fat Tigers
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Posted 05 January 2011 - 05:22 AM
Just to follow up on my car: it is some sort of weak connection in the instrument panel, I find if I strike the right side of the bezel, it starts charging and the SRS light goes out. Issue only present about 25% of the time, still too tied up with other things (lazy) to actually go in and fix it.
#7
James A Sousa
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Posted 04 February 2011 - 01:31 AM
Try the 700/900 FAQ at Brickboard - It covers quite a few SRS problems
96 855R ... 64 544...67 P1800,...12 XC70
(the first 3 are mine,heh,heh.) 525,000 Volvo miles put on 10 bricks
(the first 3 are mine,heh,heh.) 525,000 Volvo miles put on 10 bricks
#8
MistrThou
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Posted 06 February 2011 - 02:06 AM
Sounds like you both get to remove the instrument cluster and resolder the joints.
