Happy Memorial Day Weekend All:

Just a report on checking codes after replacing coil, maf, and ref sensor. I am still getting a 144 code (no load signal) on A6, so it was not related to the coil and must be a loose wire somewhere. Also, lately my temp guage just falls down while driving and my tach stopped working after going to the dentist this week. Robert DIY on you tube says these strange electrical problems are related to the ignition switch and I ordered one on FCP today. I have had the steering shroud off before, but when you pry the cover off the ignition switch is there anything I should know? Can you just pull it off or do you need a screwdriver or something? The part is original and 21 year old now, so I dont want to break it. Thanks in advance for any input.

Did you lose the Speedometer too?

Cleanup the ground 31/50 from the main fuse block back to the battery
That includes the piggyback terminal at the battery and the connections to the
frame in front of the battery and at the fuse block.

When that ground gets ratty/loose it will make the electrical system nuts.

Bill

Thanks bb will have a look. If I look around where all the fuses are I should find this ground? I only lost tach and temp needles. Tach is working again but temp keeps dropping. I'm thinking I need to remove vdo display and check plug and tighten screws...

You HAVE TO HAVE a solid ground from the fuse block back to the battery.

"Cleanup the ground 31/50 from the main fuse block back to the battery
That includes the piggyback neg terminal at the battery and the gnd connection to the frame in front of the battery"

I think your problem is there.

Get the wiring diagram for your car. It has all the subsystem circuits and
parts location s in fine detail. Search for "Volvo 850 wiring diagram TP 3907202"
(That's the 1995 850) You didn't mention what year car you have...

Bill

Bill:
I found this diagram online
http://ww2.justanswer.com/uploads/rmillerphd/2008-06-28_024006_aFinal.pdf

31/50 seems to be the first bundle or ground of three coming from the front of the fuse box.....

thx.

Hello ? What's your name?

I didn't get email notification that you responded. Maybe you should register
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Did you get the Volvo Wiring diagram for your car? It's the best.

Start at the battery and service the ground wires (2)/ TWO EACH!
wire brush so they're shiny and use some dielectric silicone and re-tighten securely. The battery and the frame gnd connection between the battery and the back of the
headlight first. You need a battery terminal cleaner/wire brush and a 10MM
box wrench for the battery and maybe a 14MM and an extension for the gnd bolt...
This might take five minutes.

Bill

Bill:

a quick check on google on the difference between power grounds and signal grounds i guess signal grounds are used on sensitive electrical circuits....31/51 is is signal ground is it located close to 31/50? I don't see the main power signal ground on the diagram......thx.

http://workshop-manuals.com/volvo/850/l5-2.3l_turbo_vin_57_b5234ft/powertrain_management/computers_and_control_systems/oxygen_sensor/component_information/diagrams/diagram_information_and_instructions/page_7660/


workshop-manuals.com is a great site. looks like the 50/51 grounds are in the same plug. Site shows resistance values for various components. The maf should be 110 ohms between 1 and 4 plug....looks like my old one I thought was bad is still good. Must have been the coil that went bad....

Here's a link with some information on how to do it.

http://volvospeed.com/volvo_repairs_how_tos/miscellaneous_repairs_tips/electrical_ignition_switch.html

Thx...looks like it just pulls off...