I’ve found a lot of janky wiring, do I have extra relays?

[Rob Dimel]

I have an ‘89 with an auto trans. I have the standard 4 relays on the pax side, but I have an additional 4 relays I can’t find a reference for near the air box on the driver’s side. We’re having a crank no start/no spark problem (going on 8 weeks now). I’m trying to trace anything electrical to figure out where our problem is. I can’t find any reference for these relays and I’m wondering what all is in the harness they run into.

I can’t post photos of it unfortunately.

 

[tech1001]

With out seeing what your taking about it's hard to say what you have . ya it's not easy to post pictures

 

[Saudade]

While you can't upload pics directly, you can post them to a picture sharing site (I use IMGUR) then include the BBCode (message boards and forums) link in the body of the message. This way we see the pics in the post and not have to click into some other site.

Here are some pics from my '88.

 

[Saudade]

If you are SURE you have a no spark condition, check the crank position sensor (CPS) located on top of the bell housing.

The fuel ballast resistor is bypassed during crank. It's purpose is to lower the voltage to the fuel pump after starting to quiet it down. You could use a jumper to bypass it altogether, but you stated you have a no spark issue.

Of course, you need to clean up any sketchy wiring. Was it caused by a previous owner or perhap something 4 legged?

 

[Rob Dimel]

If you are SURE you have a no spark condition, check the crank position sensor (CPS) located on top of the bell housing.

The fuel ballast resistor is bypassed during crank. It's purpose is to lower the voltage to the fuel pump after starting to quiet it down. You could use a jumper to bypass it altogether, but you stated you have a no spark issue.

Of course, you need to clean up any sketchy wiring. Was it caused by a previous owner or perhap something 4 legged?

I’ve replaced the CPS, coil, ICM, Distributor sync sensor, cap and rotor. Cleaned up the grounds, all the wiring in the harness going to the main 4 relays on the pax side.

What we’ve found was done by previous owner(s) and age. Some of this wire insulation is brittle and old. It was running and driving, then my son replaced the front bumper and secured some wiring hanging behind the bumper, and nothing. As we’ve worked on it, it went from the fuel pump priming as normal, now it just stays on. I’m sure it’s something simple, just can’t figure out where. It’s killing me.

 

[RCP Phx]

Sounds like a fsm would help out a lot

 

[Rob Dimel]

Sounds like a fsm would help out a lot

I just bought one on eBay. I’ve used some online manuals, but they haven’t helped (yet).

 

[Rob Dimel]

While you can't upload pics directly, you can post them to a picture sharing site (I use IMGUR) then include the BBCode (message boards and forums) link in the body of the message. This way we see the pics in the post and not have to click into some other site.

Here are some pics from my '88.

My set-up is a little different. Instead of the single fan relay/controller, there’s three relays there. The EGR solenoid and ballast are all the same.

 

[Saudade]

Yeah, I got that from your 1st post. Post a pic or two and lets see what's going on.

Where do the wires run? Two of them to the headlights maybe?

 

[Rob Dimel]

Not sure if this is going to work. Haven’t tried posting photos yet.

https://www.flickr.com/gp/197994633@N08/60tTa5im3q

 

[lawsoncl]

Not sure if this is going to work. Haven’t tried posting photos yet.

https://www.flickr.com/gp/197994633@N08/60tTa5im3q

Oh my, what a rats nest. Someone has certainly been "creative". I suspect the extra relays were installed as part of a headlight upgrade harness. Looks like maybe they eliminated the lighting connector and hardwired instead?

 

[Saudade]

"Oh my" is right!!

It's a bit hard to see the all the wire colors.

However, it looks like the one on the left (closest to the firewall), is the fan relay (Red-T and ORG-T wires).

The one in the middle could be the fog light relay (RED-LT BLU, LT GRN-T)

No idea what the last one is for. Did you pull the relay out or was it already missing?

Also, did you unwrap the bundle or was that already missing? The reason I ask is that the 3rd relay's wires are wrapped in what appears to be pretty fresh electrical tape. Perhaps it's some mod the PO did. Maybe you can trace the bundle and see where it goes.

 

[Rob Dimel]

I pulled the third relay. I pulled the split loom off to check the wires. The green wire with the heat shrink was one of our repairs. The insulation was broken, so we cut the bad section out, soldered it and put heat shrink over it.

I did some double checking on the pax side relays. If i put direct power to the fuel pump relay, it comes on with the key and keeps running. When hooked up according to the wiring diagram, it does nothing. The Latch relay will click if i put direct power to pin 86, and direct ground from the chassis it clicks/cycles. If i put the hot where its supposed to go, and put the ground from the PCM on it, it does nothing. I can attach a signal generator to the PCM ground on the relay end and trace a signal all the way to the PCM, so there’s probably not a break in the wire. I just don't think it’s getting the ground signal through the PCM. The PCM ground seems to be good. I’m beginning to wonder if the PCM is the issue.