1994 850 temperature gauge goes up, won't start

Volvovlo · Post by **Volvovlo** » 08 Oct 2014, 19:19

Is it possible to reset my ECU? Or would a new thermostat solve my problems? It ran fine without one for a few weeks.

Post by **Ozark Lee** » 08 Oct 2014, 21:26

I'm not sure if the instrument cluster test procedure is valid unless the cluster is a VDO brand.

...Lee

Volvovlo · Post by **Volvovlo** » 11 Nov 2014, 01:48

I found the problem finally. I hope this helps anyone else with the same problem that caused me frustration and cost hundreds of dollars for over 5 weeks. Turns out it was a loose wire going into a relay on top of the radiator. It wasn't even broken, just disconnected. It had fallen through the plastic connector so appeared plugged in even though it wasn't. I found the problem after wiggling wires and hearing an electrical sound. It still took me a week to find the exact cause. Car has been running fine for over a week now, I hope this helps anyone else with the same problem. If your temperature gauge goes up and your car will not start, check the wiring around the top of the radiator!

jonbarwick · Post by **jonbarwick** » 09 Dec 2014, 14:02

Volvovlo!
I have had this exact same problem for several years on my 1995 850 (UK). Dealers, mechanics, electricians - none have ever found the fault!! As soon as you mention the temperature gauge they look at you odd!
Please could you post or send me a pic of exactly what you found wrong? It would be very much appreciated.

Cheers
Jon

charlie33 · Post by **charlie33** » 07 May 2015, 11:02

Hi ive got the same problem when the temp gauge on start is erratic it wont start but when it does nothing it starts currently not starting checked wiring above Radiator and it seems fine also changed cam and crank sensors and fuel fuse its been fine for 3 weeks now the old problem has returned any help would be much appreciated

Post by **misha** » 07 May 2015, 15:20

Replace ect sensor with oem.Oem is made by Valeo and only aftermarket replacement should be Vernet.Nothing else will work on these cars.
While you're in there,replace thermostat as well with oem 90 degrees unit or at least 87 degrees from turbo cars.

Post by **dosbricks** » 07 May 2015, 19:28

Charlie, welcome to the forum.
The connector to my temp sensor--engine side--fell apart when I changed the ECT. Old brittle plastic. There was green corrosion in the connections. I replaced the entire plug connector with two male/female round wire connectors and used heat shrink insulation around them. This sporadic no start problem sounds like a wiring issue. Check the internals of the ECT and CPS connectors.

Post by **misha** » 08 May 2015, 02:09

Yes...dosbricks is right.It can be just a connector that it's bad or corroded.

charlie33 · Post by **charlie33** » 09 May 2015, 05:40

Thanks guys I agree its electrical checked connections and they seem fine also feel its something to do with the temp as the video on the previous page is identical to what my car does when it doesnt start. .I am reluctant to change the ect as it didnt help him. He says he found a lose wire to one of the relays above the radiator. Mine all seem fine but would like to know what relay it is as I would just replace that. I dont want to replace all of them as that seems silly also I found a disconnected wire below the battery but I cant seem to find where it goes.

Post by **misha** » 09 May 2015, 05:44

It's and aditional wire for some device.It's not factory wire.

1994 850 temperature gauge goes up, won't start

Re: 1994 850 temperature gauge goes up, won't start