Question about 1990 Volvo 740

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I'm having a problem with my 1990 Volvo 740's speedometer. It fluctuates erratically and the odometer does not work either.

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Check the connection at the speed o sensor. It's in the differential cover, about 3" above the filler plug. Be sure it's mechanically secure, and check the contacts (both sensor and connector) for signs of corrosion or oxidation. As much as possible, examine the harness for any signs of a break or tear, or for signs the wire might have been cut. If it's not wiring, then it's either the sensor or the speedometer head (which is electronic). Possibly, the power supplied to the speedo head where it's mounted in the dash cluster is intermittent. The speedometer in my 745 with 160K has been jumping around a little on the highway. The cruise control would try to follow the erratic speedometer, then disengage. I suspected a broken wire at the sending unit. What I found was a burnt wire at the sending unit. The wire had grounded out on Volvo's safety wire. I suspect that the safety wire slowly eat through the insulation on the wiring, causing it to ground out. The plug was melted and an inch or so of insulation on the green stripe wire. Make sure the safety wire is not cutting into the two wires on the sending unit at the back of your rear end. [Response: Scott] Check the instrument cluster grounds under the dash and in the right footwell. In 88 there were some 700 series cars that would register up to 60 mph while sitting still and the grounding problem was the cause.

Posted on Jun 29, 2009

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Hi, I have a volvo 740 made in belgium 1991 model. The speedomete spent a few months fluctuating wildly, sometimes working well, sometimes not at all, sometimes stuck on 140 km per hour. The odometer...


There should be a speedo sensor on the transmission somewhere. I don't know exactly where it is located. I believe your speedo is all electrical so the sensor on the transmission sends a signal to the speedo head. You can go onto some parts stores websites and see if one is listed for it, if it is, I would try replacing that first. I don't think the part should be more then $50 or $60 but you never know with Volvo. Good luck.

Jan 02, 2011 | 1991 Volvo 740

1 Answer

1990 volvo 740 speedometer quit working


There is a speed sensor on the rear diff cover that may me shot, however it is regulated by hertz so the dealer is the best place to see if the wires are okay. That sensor can be costly.

Aug 02, 2010 | 1990 Volvo 740

1 Answer

Owners manual


the odometer part of the speedometer has more than likely broken, or is just work out. you can't replace just that part of it either, you'll need to look around or search google for a replacement speedometer. bear in mind that some laws come into play when replacing the speedometer / odometer on a vehicle as well.

Sep 24, 2009 | 1991 Volvo 740

1 Answer

Erratic/non functioning speedometer


replace the battery, you can drive the car to a part store and have them test it first(they usually won't charge you)

Aug 16, 2009 | 1991 Volvo 740

2 Answers

Odometer inop and speedometer erratic over 50mph


Yes your speedometer, and odometer are controlled by your speed sensor.

May 20, 2009 | 1993 Saturn SW1

2 Answers

Speedometer erratic/intermittent


I don't know what is causing this problem, but I know phil140701's answer is completely wrong on two counts. First, 740 Volvos starting at least in 1986 have electronic speedometers and no cable. There is an electronic sensor on the differential which sends a signal to the speedometer cluster. Second, if it were strictly mechanical with a cable then the voltage regulator could have no effect on it at all.

Dec 29, 2008 | 1991 Volvo 740

1 Answer

Odometer does not work


This is a common problem with all models of volvo, with the non digital odometer  pre 1998,, there is a tiny nylon gear deep inside the odometer that needs to be replaced. Your dealer will not fix it, but will put in a new one for you as the cost of fixing in labour is more than a new one,, My solution is much cheeper,, I have
many low milage VOLVO odometer/instr clusters, a few hi'r km 1s


ODOMETERS FROM 1987-PRESENT
I have many pre 1998 Volvo instrument clusters, most with Very low milage, almost all in Km, I have most models of Volvo.

at these prices IT'S A GOOD IDEA TO HAVE AN EXTRA ONE , comes with detailed instructions -with pictures-on how to remove your old one and re-install

just for example
I have 4,, 1994-1997 850/s70/v70 /c70turbo with less than 10,000 km
2 1994-1997 850/s70/v70/c70 non turbo with less than 10,000 km
1 1990 740 -940 turbo with less than 4.000 kms

I also have many Volvo instrument clusters from 1987 to PRESENT with varied milage,,let me know what year and model and milage you are looking for,, I will have something close

WILL SHIP ANYWHERE IN N.AMERICA

Dec 12, 2008 | 1994 Volvo 850

1 Answer

1989 volvo gl 740 speedometer and odometer


Your problem is NOT a fuse. The speedometer receives an electronic signal from an analogue transmitter mounted in the rear differential. It's the little button in the rear diff with two wires attached to it. Check to see if the wiring is chaffed or broken. If not, then it's probably the transmitter. A competent mechanic should be able to replace one for less than 200.00, parts and labor. If this does not fix it, then the problem is in the head, which can be expensive. You might get a used head if you can get a 90 day guarrantee on the part from the salvage company.

Good Luck!

Oct 09, 2008 | 1989 Volvo 740

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