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Temp gauge sender Ohm values.

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BlackBetty
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Posts: 240
Joined: Mon Jun 03, 2013 11:53 pm
Location: NW Ohio

Temp gauge sender Ohm values.

Post by BlackBetty » Wed May 16, 2018 9:58 pm

Hi all,
Does someone have the Ohm values for the dash coolant temp sensor? I did find the ones for the blue (ECU) sensor, 3-400 at operating temp, but can not find anything on the other sensor.. got some funny things going on with my coolant temp..actually, I do not get any Ohm value on that sensor, including a short , however the gauge does kinda work, pulling the connector off and shorting it out does leave the gauge at cold....however the gauge does go up and down starting and driving.. just runs hot .. new radiator and thermostat, recent pump and clutch and hoses..

This is on a '88 with a -B35 running Motronic 1.3
Pete
1988 Black 635 csi, 130 k miles

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Martin S
Posts: 59
Joined: Mon Sep 07, 2009 6:51 pm
Location: Sweden

Re: Temp gauge sender Ohm values.

Post by Martin S » Sun Jul 22, 2018 1:17 am

Just had a small breakthrough so I thought I'd post my findings.
My car is an -84 euro and has the double connector type. Should be the same for all with the same cluster gauge I guess. Under the grot I found It is marked "VDO 803/1/22"

This is nowadays called VDO 323-803-001-022D

Acc to VDO data sheet:

TU00-0770-5104620 Temperature Sensors_short_version.pdf

It has the attached charachteristics.
You need to disconnect the cable to measure it.

Mine checked out at room temp so I'll see tomorrow if it is also ok when driving.

Just changed waterpump and thermostat and it runs hot acc to the gauge... I dont trust it... Yet.. :)
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VDO 323-803-001-022D characteristics
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Martin S
Posts: 59
Joined: Mon Sep 07, 2009 6:51 pm
Location: Sweden

Re: Temp gauge sender Ohm values.

Post by Martin S » Sun Jul 22, 2018 2:31 pm

My temp sender and cooling system seems to work fine. It goes to 85C (about 59 Ohm) and stays there.
The "overheating" was a faulty temp gauge in the cluster. Took it off the circuitboard and cleaned the terminals and ground, and it now works fine. (It used to wander up almost the red marking when slowing down, and sometimes flicker back and forth)

Now that I measured the temp sender I see it only varies between 85 and 90 deg during driving.

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