Cluster problems, really need advice

[74chevylvr]

Need advice:. On my 74 swapped in a full harness from a 78. Swapped the oil sender for an electric one, swapped the temp sensor. The cluster is from a 79. Circuit board looks good.

The only thing that works on the cluster is the gas gauge, the fasten seat belt buzzer and the left hand turn light. Nothing else.

I really don't want to spend hundreds just throwing gauges at the problem

Any advice? All of the light bulbs are in, however only the left indicator light works

[SunSoaked]

Dakota Digital. You won't regret it.

[Dead Parrot]

While the physical cluster plug and socket stayed the same from 73-87, the pin assignments changed each year and from model to model in the same year. You need to figure out the pin layout for your 79 cluster and move the pins in your 78 plug to match.

[Palf70Step]

These may help you figure out the differences between the different years wirings.

[74chevylvr]

Thanks. The pinouts look the same 78 & 79. Clearly the board is getting electrical or the gas gauge wouldn't work at all. I just can't figure out why none of the other gauges are working. Speedometer is clearly a cable issue.

Was thinking to just buy another circuit board, new clips and new lights. Other than that I am flummoxed.

One other question. The oil sender connection on the harness has what looks to be a rubber cap with two connections in there. The oil sender oil has one. Should I cut the connection off and put a spade on?

[Palf70Step]

The gauges side and fuel tank/speedo side get the 12V from different sources (pins) One of the things I found is to check the circuit board plastic thing. It is common for them to have cracks and all that will prevent circuit flow. You could always take and wire the stuff in the dash plugin directly to the individual points. I did that with the left turn signal on mine. I also wired in a better ground connection to the harness connector.

[rgunlock]

Another place to check carefully is where the harness connector plugs into the back of the housing. The gold leaf connections where the plastic circuit sheet folds into the connector hole sometimes peel off the plastic leading to bad connections.

[74chevylvr]

The circuit board is good. I just swapped it over this weekend to another plastic case and it was clean. If I can figure out do I clip the two prong connector with a single prong or just plug the sender into one of the prongs that would be very helpful

[Palf70Step]

I drew this out when working with mine, maybe it will help