temp light, 1994 440SE

[billofdurham]

The 4 series is the only one I don't have wiring diagrams for.

One thing that did occur to me is that your vehicle has a diagnostic unit in the engine compartment. If the engine temp sensor threw a fault code it will be stored in the unit and could still be influencing the light/gauge. Have you checked for fault codes or erased them?

Bill.

[liteman]

Hi Bill

Found and played with the diags unit. An interesting and useful built in unit most cars should have, you have to pay alot to get a garage to connect a diag unit to check codes.

There were three sockets wired up on the unit, 2, 3 and 7

Results;

1 - 1 - 1 from socket 2 (Fuel codes)

nothing from socket 3

1 - 1 - 1 from socket 7

Which indicates all is ok apart from socket 7.

I donot know what socket 3 and 7 are for, Haynes manual is missing lots of stuff, no mention on this diags unit in the engine bay.

I had another run to Southampton with four biggish blokes, testing the speed to around 80ish on the motorway, with no problems so cooling systems appears to be working well. I did have the heater on in the car, so you can imagine the inside temperature and comments. I have electrical diagrams which I donot understand so cannot trouble shoot these.

I shall try to find someone who understands these, but what do I need to ask?

Thanks for all your help

Mike

[billofdurham]

My book only shows tests on socket 2 so I don't know what 3 & 7 are for.

I was hoping for 1-2-3 on socket 2 which would have indicated a previous fault on the temp sensor.

I mentioned the wiring diagrams trying to answer your question about a temporary wire to the gauge. You need someone to find the wire from the temp sensor to the gauge so you can jumper a temporary wire in.

I was going to suggest what you have done to the light as they can be a real pain.

I hope it keeps running and if you find how to put a temporary wire in let us know the result.

Bill.

[liteman]

I have solved my problem of a high temp guage and a perminant temp light.

The solution is to replace the PCB behind the temp gauge. To do this I removed the instrument panel and dismantled it, replaced a blown PCB with one from a scrap yard, put it all back together and hey presto, an easy task (20 minutes at most if you take care). This is for UK 440, right hand drive.

You do not have to remove the steering wheel to remove the instrument panel. just lower its position.

1. Remove two clipon covers under top of instrument panel with small flat screw driver

2. Unscrew the four screws, two at top and two at bottom, one either side of steering wheel, which hold in the instrument panel cover. Pull the cover over to right side of the steering wheel, then twist it so it hangs down the right hand side of the steering wheel safely. You can unplag the wires attached, but make sure you mark the position of the plugs etc. for when you put it all back.

3. On the right hand side of instrument panel remove the two screws holding instrument panel in place. Pull the panel outwards using abit of muscel. The left hand side of the instrument panel is held in by a sort of clip which will release when you pull the right hand side of the instrument panel out first.

4. Put your hand in behind the instrumet panel to remove the speedo cable. Twist the connector (screw head) quarter of a turn and the cable will withdraw from the instrument panel.

5. You should be able to juggle the instrument panel over the right hand side of the steering wheel to see the wire connectors. Mark the positions of the connectors before removing them to help you when you replace them afterwards. There should be two block connectors and a two wire connector. Remove all after marking their positions allowing you to remove the instrument panel to work on.

6. With the instrument panel removed from the car, unscrew the eight srews holding the instrument panel casing together. Pull the clear plastic facia from the casing to reveal the gauge dials, be careful not to damage the dials.

7. On the back of the instrument panel are four small nuts, which should be finger tight. unscrew these and remove to one side.

8. Removing the temperature gauge............... note: there are long pins which are attached to the temp gauge which plug into sockets on the underside of the large coloured flimsey PCB through the instrument casing, try not to break them. You cannot see them till you remove the temp gauge.

9. Pushing the four screw studs (you just removed the for nuts from) through the casing which pushes out the temperature gauge. As you begin to remove the gauge check through the gap to see a PCB, this can either remain in situ or can withdraw with the gauge. With the gauge out you can see how simple the whole thing is and how easy it has been constructed.

10. My PCB had a slight discolouring around some of the surface mounted componants, when viewed in certain light.

Replaceing the instrument panel is quick and easy, when pushing the actual instrument panel back into the dash push it in squarely and the left hand side clip will engage automatically.


For the fault code list for the 440, you can find it here...

http://www.troublecodes.net/Volvo/

volvo diagnostics

Socket 1 is the alarm & immobiliser
Socket 2 fuel codes
Socket 3
Socket 4 ABS
Socket 5
Socket 6 cruise control
Socket 7 SRS

I only have 6 sockets so don't know why it identifies seven sockets!!!!

I am convinced the 440 and cars of its age are easy to work on and maintain, but this DIY facility dosn't earn shareholders etc much dividands, hence bloddy ECU's and electronic management systems which all fail and are costly to repair/replace by dealerships ONLY.

I hope this might help someone else out there someday.

[billofdurham]

That was one I overlooked. Good to know you have resolved the problem.

I intend putting your very good write-up in the Repair Database but, at the moment, there is no provision for 4 series repairs. I have taken this up with Matthew.

Bill.

[liteman]

Hi Bill

Just a final note, on closer inspection of the small PCB that I replaced.

I noticed a dry joint (a soldered joint which had become unsoldered or was not soldered properly in the first place) on one of the surface mounted componants. I'm going to resolder this and hold the PCB as a spare, I doubt I will ever use it now.

Thanks for your help

Mike