I have the intake manifold off my 1981 240. Below the manifold intake ports on the head are three sensors of some kind: one at the front with two wires coming off of it, one below number two cylinder with one wire coming off (engine temp sensor, I think.), and one sensor at the rear with two wires attached (cold start injector switch, I think.). The single wire coming off the sensor below #2 has no insulation on the visible part. It had some, but it all crumbled off in little pieces when I rubbed it between my finger and thumb to test its integrity. So now two or three inches of bare wire leads from the sensor. The wire then disappears into the wiring harness. What should I do? I can tape the bare wire, but it’s probably rotten down into the harness too. All the other wires I’ve come across seem to have good firm insulation, and as far as I know the car shows no suspicious electrical problems. Thanks in advance.
DougC

I have an '82 that I just changed my harness on. You will be very suprised at what you find when you disect the old harness. I have no idea how my car continued to run with all of the insulation off of the wires inside the harness.

http://www.linkline.com/personal/dbarton/WireHarnesses.html

Dave Barton sells used newer harnesses. He is currently out of the 81-82 k-jet harness but keep checking. Harnesses come up on ebay and the clasadds at this site as well. Make sure you check the part number on the harness you purchase, the newer harnesses that dont degrade have different part numbers, your dealer can give you specifics.

If you are serious about keeping your car, which it sounds like you are if you are going through the trouble of changing the breather box on a k-jet, you definately want to replace the harness.

MRE
--
'82 DL - 151k, '93 945 - 99k

How long does it typically take a professional Volvo mechanic to replace the wiring harness on a 1981 K-jet? If I multiply by about five, I'll have the time it'll take me. But then again, I already have the intake manifold off ao that might save me a little time. What does it typically cost all said and done, doing it at home?

A good used one costs about $150 (new ones go for maybe $280, or proabably more), the ones that Dave Barton sells are great, becuase he includes directions with labeled diagram, which makes the installation very easy. Even without directions, it takes about an hour or less. Just leave the old one on, and give it a good look over for placement before you start taking it off and putting the new one on. You've already done most of the work, by taking of the intake manifold. When putting the manifold back on, it gets kind of fun routing the fuel injector lines and wiring connections through the correct spaces on the manifold. Make sure you take a good look at the starter connections before you take them off, so you'll get it right when you put them back on.

-Bruce

Here's where a video or a series of photos may help alleviate some of the head scratching.

I've fixed that wire on every 1 of our volvos. My cheap fix is to split black fuel line lengthwise push the bare wire inside and tape it up, lasts a long time for me and nearly free.

You can buy new or slightly used harnesses on this board, better gear up for the job because once the biodegrading starts, its time!
--
'83 244GL 210K

Your lucky if you only have one bad wire on your harness, probably easiest to get the correct length of new wire, and splice it in right after the big gray connector, and either feed it through the long black plastic sleeve, or bypass it, and go directly to the terminal. Others on this board probably have more expeirence with the dreaded volvo crumbling harness disease. It is definetly a good time to check your harness throughly. A good wire to check is the red wire that goes to the alternator, typically goes bad when it passes under the water pump area.

-Bruce

Can anyone advise how to splice this wire with a replacement section for this wire only? I would like to splice right up to the gray connector but am not sure how to trace the wire through the existing harness up to the gray connector at firewall. Thank you!

Don't go through the harness itself--if you attempt to open it you'll likely find other deteriorated wires that may crumble when you mess with them. Run a length of yellow wire from the sensor along the harness and then snip the wire at the junction block leaving a 3 inch pigtail--now solder or tube connector the new wire to the engine side pigtail you made at the junction block. -- Dave

Dave - thank you for this response. Appreciate the help.

Any tips on how to know which wire is the temp sensor wire up at the junction block? I believe the wire at the sensor is yellow in color (will have to verify), but someone has spray insulated all the exposed wires at the block. Maybe I can peel back the spray insulation and see the original color of the wire. Just want to make sure I splice into the correct wire.

Thanks

I looked at both my '84 245Ti and '80 245DL -- the yellow engine temp wire is the second one down (black wire above it) -- in the row closer to the front of the car. -- Dave

That's the disease I was wondering about: the dreaded Volvo crumbling harness disease. I hope to learn more about specific symptoms. Thanks. DougC