1988 dash rewiring problems

Not wrong… but obviously you need to double check your connections. I can’t speak to the accuracy or helpfulness of the wiring diagram- but here are a few tips.

Start with the senders coming from the engine harness. Make sure they go to the right gauges. Add fuel sender.

Check 12v batt power (and orange alt wire, if your harness has one) and make sure it comes in to the dash via the ign breaker, then goes to a 12v buss. From the buss it should go to the key switch (Batt) and to any switch that should work while the key is off. Lights, bilge, blower, etc. Outputs of those switches should go to to those components. Lights on the gauges should be fed by the light switch.

You didn’t mention a buss for ignition power but it will be one of the more useful things to add. It should be fed by the ign terminal of the key switch. Outputs should go to the engine harness, and to every gauge +. Also to any switch that you only want to work with the key on.

Everything worked before I began the process, I was just having some voltage drops when the system was loaded.  After reading about grounding issues I decided to start there and if that didn’t fix the problem then trouble shoot from there.  That said, I’m working under the assumption that all the senders and power are correct still.

Haha, good advice. I’ll rewire that part today and see if I have any luck

I finally made some forward progress this weekend.  After some trouble shooting with the multimeter I figured out my idiotic mistake that caused several hours of headache.  I replaced my terminal block with a larger one and failed to realize it didn’t have a common connection so not everything was getting grounded.

I too have stared at that diagram until half blind.  I finally ended up wiring it as follows (which as best as I can tell is how it is shown in the wiring diagram)

1/2 cup of Dawn dish soap and 5-6 gals of water in the bilge.  Drive boat around for 15 min (even on trailer).  Empty and rinse.  Bilge is clean and shiny.

gibson1525 wrote: Haha, Yes sir, it’s on the list

KENO wrote: After blowing up your diagrams, staring at them till I was bug eyed and half blind because of the blurriness, I think I like the way you rewired it before some schmuck( AKA me) said to wire it back to the diagram last year.  Now with the ground side of things fixed, I'll guess that you have a pump with 3 wires, maybe Brown Red (or Brown/White) and Black Black to ground Brown to Manual switch on dash Red to Auto switch on dash And no interconnection/jumper between the switches other than the daisy chained power input wiring In other words take out your jumper and see if everything works If that doesn't work...............what is the pump brand and model? Integrated float switch or separate switch?

Well that configuration did it, I have an almost fully functioning electrical system again, much appreciate so the help!

The clock doesn’t work but I’m taking this as a win for now. I’ll tackle that later

It’s a black face clock

KENO wrote: Does it look like this one? If so, this one is desperately looking for a new home in a good looking dash. I think yours qualifies, so send me a PM and it'll show up at your house next week  It came from a Supra and thought a new life in a CC might be nice Since it may work for 10 minutes or 10 years or something in between, I can't see charging anything for it.

Yep that’s it, I’ll send a PM

On a side note, has anyone ever had success rebuilding these clocks? A quick google search makes it seem possible

I'd probably do pretty much what you did with the clock and unwire the voltmeter and run jumpers to it direct from the battery and see if it reads battery voltage. You could compare it to a reading on a multimeter hooked to the battery..

Sounds like the gauges are winning