Hi, I have a 1970, the gauges are in terrible condition. I have a 1974 set of gauges that are much nicer I am going to replace them with. The early set has individual left and right blinker bulbs located on the tach gauge. The later tach gauge has one bulb shared by both sides. My question is: is it ok to jumper the wires from the left and right blinker to the single bulb in the newer gauge? I just don't want to do any damage.
Thanks, rob

No, not ok. You have wires for left, right and a common, with a jumper. Connecting them together will damage something. My advice would be to sell the 74 gauge and either get a better 70 gauge or have yours restored. The early cars that have the the two different arrows are cool...keep it that way! Use the correct part for your car not just what you have convenient, having the right part is = priceless

Sell the 74 stuff on here, but first put up a WTB ad in the Parts forum.

Yah, tying the two wires together would leave you with bad results. If you were set on using these gauges, it could be done with a few diodes

That answers that.
Thank you!

Oh crap!

My situation is just the reverse. I'm going to temporarily install the ['modified-by-Tim'] early silver dot gauges in the ['75] 'BB' ...

... should I leave the wiring to the dash turn indicators disconnected then?

In your situation, you can tie an extra wire into the hazard light switch

I have the two bulb gauge. I really like it over a single bulb set-up.

Run to radio shack and pick up 2 diodes. Try to find them at 15 volts and 3amps or greater.

I would assume that a LATE wiring harness is much easier to modify to accommodate the older gauges. . just jump the dash bulbs from the other flashy circuits?

You should be able to wire up the single indicator like the 74+ cars by connecting one side to the 'K' lead (this would be the common leads to the individual L and R indicators) and the other side of the indicator to chassis ground.

See the diagrams below.

My $0.02 is to get a nice early tach with L and R indicators. I had a 74 with the single indicator and did not like it. So I obtained an early tach and swapped the later tach and faceplate on the early tach.

BTW, tying the 2 wires together will result in the indicator never turning on and all 4 turnsignals (Left/Right, Front/Rear) coming on at all times.

As far as using newer gauges - I was trying to use stuff on hand and be cheap. However I do like the look of the older gauges better. This leads to a part two question. With my older two bulb setup sometimes when I would turn on either left or right blinker, sometimes both sides would blink. Sometimes the correct side would blink and after a few seconds then both sides would start blinking- only on the dash, on the outside lights it was correct. Is that a ground issue? I've checked all the grounds I can find. Is there one I may be missing?

You say sometimes, how often does this happen?

If I don't connect the dash turn indicator lights (early gauge in a late car), will this cause an issue with the flasher? (not 'seeing' a load on that circuit)?

Not a ground issue. The blinker unit is bad. Notice the in the 70-73 circuit the common connection of the indicator lamps that go to the 'K' terminal of the flasher relay. This part of the relay is not working correctly.

For example, if you disconnect this common wire between the indicators, both indicators will light at the same time with a lower intensity since 2 lights in series get 1/2 the battery voltage. This is what you are seeing.

2 solutions:
1) Buy a new flasher.
2) Remove the common wire from the flasher to the lamps. Then tie the common connection of the lamps to ground (ground lug is on the back of the tach case). Then swap the 2 lamps as they will flash L for R and R for L. Notice in the 70-73 circuit that the R indicator is connected to the L turnsignal bulbs and L indicator to the R turnsignal bulbs.

No, the 'C' or 'K' terminal on the flasher is an auxiliary contact for the indicator and doesn't need to be loaded with the indicator bulb. I'm not sure of the exact purpose of this extra contact but you can bypass it.

I did this "early gauge in a late car" swap. I simply connected the L indicator to the L turnsignal bulb connector at the 4-way flasher and the R indicator to the R turnsignal bulb connecotr at the 4-way flasher. Then connect the other sides of the indicators to ground.

Awesome information- I would not have been ablo to figure this out on my own.
Thanks!