Volvo RWD 700 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 11/2004 700 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

Getting wiring right for Temperature Gauge 700 86/87

posted by  someone claiming to be John on  Fri Jul 27 16:51 CST 2001 [RELATED]

My Dad and I took on a project of replacing the blown motor in my 1986 740 turbo with one that has low miles from an 87 740 turbo...We got most of the wiring to match and it runs pretty good. But - the temperature guage is not working.

The wiring harness is a combination of both 86 and 87. I believe that the temperature sending unit(in the engine block) is from the 87 and has two connectors. One wire is black/yellow. The other is white/yellow. It may also be helpful to know that there is a black/yellow wire (as well as a blue one) from the 87 (?) harness that doesn't have a mate with the 86 part of the harness that runs to the inside of the car. ANy help to mate the two harnesses to get this solved would be greatly appreciated. Would this also have an affect on the coolant temperature sensor as the electric fan has been tested and works...it just doesn't come on under normal conditions - only when tested. Help! Thanks in advance for helping me with my latest challenge.







  •   REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

    Re: Getting wiring right for Temperature Gauge 700 86/87

    posted by  someone claiming to be John F. Randstrom on  Sat Jul 28 06:32 CST 2001 [RELATED]

    I replaced the engine in an '86 740 with a '90 B230F engine and used the original engine wiring harness and sensors so it was plug and play(pray?).

    In regards to the coolant temperature gauge not working, replace the '87 temperature sensor with the '86 one wire temp. sensor. The '86 sensor lead should be a yellow/white wire. Make sure the sensor lead is connected properly at the grey connector where the looms plug together.

    I believe the electric fan on the radiator only comes on when the coolant temperature reaches 206 degrees. The fan shouldn't run under normal situations.

    I can't help you with the two extra leads in your '87 wiring harness. You might be able to trace them through the harness to see where they connect.

    If you have any additional questions just ask and I'll try to help.






<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.