Hi. My car is a 1989 240DL. I've decided to upgrade the electronics a bit. I'm adding a new radio/speakers, tach, volt and oil pressure gauges. The gauges came from the gauge cluster of a turbo car and have all the wiring intact up to the connector.

Several posters have helped me understand how the gauges and tach should be wired/installed (thanks to you all!!), but when I was beginning to install the gauges a question came to mind.

Since the gauges are already wired in a single harness for light and power, would it be possible to use the three prong connection on the back of the tach to power/light/ground the new gauges? A poster here explained the three terminals on the top back of the tach were to light/ground/power a small clock. Since I'm not installing a small clock, those connections would be free. My thinking would be to remove the turbo gauge, leaving the wiring for the voltmeter and oil pressure intact. Putting spade terminals on the ground, power and light wires from the gauges and connecting those wires to the three terminals on the back of the tach. I would still have to run an independent wire to the oil pressure sending unit.

My concerns are:

1) Would it even work?
2) If it did work would pulling power for both gauges overload the tach circuitry?
3) If the power demands would be too much, could I just run the lights (off/on/dim) through the tach connections, powering the gauges from a key-on source?

Using the tach connections would make the installation much easier and cleaner (especially for the lights!) instead of splicing into the existing wiring harness to light/power the gauges.

Thanks!!

So, if you are adding three gauges, are you removing or relocating the radio? I'm guessing you're putting the three gauges on the top of the center console where the radio is usually found (like on my '92). Sounds like you are also upgrading the radio. Where will you install the radio, at the bottom of the center console like an '83 240 GLT?

For the fun of Volvos,
Mike
--
'83 245 GLT, '92 245DL, '90 760 GLT

Hi Mike,

Tach, oil pressure and voltmeter. Tach is replacing the old large clock. The other gauges are going by the new radio in the upper radio slot.

Seems that you are eliminating a clock function.

I am looking into pulling an '83 center console front cover. It has a deep bottom recess used for its radio. This may offer room to relocate a radio and free up space on the upper console for three more gauges plus the two blanks. I don't have a workable large tach, but I do have a small clock.

For the fun of Volvos.
Mike
--
'83 245 GLT, '92 245DL, '90 760 GLT

Wiring the gauges from the clock socket on the tach would seem a nifty shortcut, except for the fact the clock needs power when your car is shut off. So option 3 is reasonable, just tapping the clock socket for its lighting. When I did this, I grabbed the lighting from the upper front console, where brown and black wires abound for the switch panel illumination. The only benefit I see is if you short it out accidentally, you won't be chasing for burned traces on your instrument cluster -- just the usual fuse or dimmer rheostat will suffer. The turbo's gauge harness was of no use in my NA adaptation: Oil, volts, and manifold pressure.

--
Art Benstein near Baltimore

"I love the smell of gasoline in the morning, afternoon, or evening.
This may explain why I see green and blue elephants sitting on the roof of the house." - Research

I'm "all ears". I have the same project in mind.

For the fun of Volvos,
Mike
--
'83 245 GLT, '92 245DL, '90 760 GLT

Okay, I'm bored. Is there a "start to finish" step by step instruction to install two guages where the blanks are on the dash to the right of the other guages? Also, where do I buy the guages? I am thinking oil pressure and amps? Art, what do you got? ( I'm almost afraid to ask.....trael graduated in miileseconds, relative speed of other cars guage, intensity of UV rays coming into the car!!!) Remember, Art talk to me like a third grader. By the way that was the toughest 4 years of my life...teh 3rd grade.

Hi Ken,

toughest 4 years Funny! Like the "spent a week in Philly one night" line.

I know this has been done many times, but I've never seen a write-up as such. I think most folks start at the pick'n'pull yard when the owner of a 240DL goes searching for good stuff, and sees those gauges in a turbo, right where their radio is, and the radio (if actually still in the junker) down where their catch-all is.

I've seen them on ebay too. When you search, try "both" spellings of gauge. I found some ten years ago on ebay doing that, using the "guage" variant, and was the only bidder due to the seller's spelling.

Also try searching the forums -- I just don't recall a write-up. If you spot a turbo at Crazy Ray's, be sure to get the oil pressure sender, or the real use of the upgrade will be lacking. With the sender, get the little 45-degree street elbow. Now, suddenly I realize yours is a '90, so you'll need an adapter from the old B21/23 block oil port threads (1/8" pipe) to M14 threads used on your B230. Check out egauges.com for that piece. The fun of the upgrade is not having it done, but doing it.

--
Art Benstein near Baltimore

A boiled egg in the morning is hard to beat.

Art

Boy, are you on the money.....doing it is the fun of it. Thanks for the mild advice ( as opposed to sage! ) as usual. I knew I could count on you. I was, though, hoping you'd say I could order a kit through Brickey Joe's Warehouse or something but somtimes I am just lazy. I will do as you advised and hope I can do it, but know where to come if I can't. Are you an engineer in real life? Just curious, as you remind me so much of my recently-deceased beloved father-in-law from Kansas. You know, you can listen between the lines and learn alot about a person. Thanks again.

Ken