camerons_dad

I've searched a lot and not found the same situation as we are in. Logicon has no power and all fuses / circuit breakers are good. We're checking at the "l" wire (LgB) on connector G-01 per the trouble shooting guide on page 15-99 on the factory service manual.

Background. 1988 RX7 Turbo II, manual, no ABS, no AAS. Basically stock at this point. Runs good, occasionally get the click, click, start thing but otherwise everything seems to be ok. Car was also missing the blower motor housing so never had heat or defrost since we've owned it. Trying to piece together all that now. AC was removed by us when we put in the new engine.

We purchased a replacement blower housing complete with sub harness and relays. Now we have two of the sub wiring harness for the blower but they are different and cant remember what one came with the car. One has connectors that more closely match the cars harness colors so we used that one and transferred the missing relays over.

The factory service manual page 15-98 shows an optional "IG relay" and there is an empty four-wire plug we're assuming is for the optional "IG relay". The Haynes manual calls it an "IGN relay". This also shows up on the harness diagram on page 50-67.

Anyway there is an empty 4-pin connector that we are assuming is for the optional IG relay but since the car is not Auto and non-ABS do we need it?

Could this missing IG relay be the reason we have no power to the logicon? Can we jumper the missing relay perhaps?

Thanks for the help, sorry for the long text.

satch

iTrader: (1)

There are a total of 4 fuses. Cooling fan fuse powers the Yellow wire and is found at the blower motor at connector F-50 (has power w/key to on).

Heater fuse wire is Blue runs to the same connector, F-50, and has constant voltage.

Cigar fuse powers the L/B wire which has power w/key to ACC or on. The wire is found at the logicon but it first runs through connector F-01 before making its way to the logicon.

Illumination fuse should not be your problem and it also runs to the logicon and the W/G wire, which has constant power, runs through connector FI-02.

The logicon places a ground on the L/Y wire to turn the ex-hi fan on. And the Black wire is a constant ground. Both are found in connector F-50 at the blower housing.

jjwalker

The Missing IGN relay you speak of is for auto trans vehicles with the optional electric fan...shouldn't be causing your issue.

bigrodt

I think I may be having some similar issues! I will be monitoring this thread for more information.

camerons_dad

Time for an update, IT WORKS! All of it works only one led on the logicon is burnt out everthing else works just like new. We're trying to get the car back on the road for Senior Prom.

First of all thank you all for the help especially satch, the harness diagrams on this car are the most confusing I've ever worked with. What we learned:

- Our car is a Turbo II so no yellow wire at the F-50 connector the power wire is B/Y and was not the problem.

- The missing IG relay from the used blower motor assembly was the problem. Without the relay or supporting circuit (our car is non-ABS and manual trans) the power was not passing from B/Y at F-50 to Lg/B at the Logicon. We bypassed the missing relay by making a jumper Y to Lg/B at the IG connector.

Now we just have to put the rest of the interior and radio back together along with the new AFR gage. 13 days and counting.

bigrodt

Too bad you did not take pictures.....I am having problems with my logicon and my car is bone stock. I will check the fuses this evening..

camerons_dad

Bone stock with what options and configuration?

Auto is different than manual is different with ABS or AAS is different than convertible I think.

I've look at enough different wiring diagrams I might be able to help with diagnostics if your a little more specific on the configuration you have.

Also I think Cameron did take a few pics, might still have them on his phone I will check...