I was chasing an intermittent electrical gremlin in my 89 Formula 350, the story can be seen in my prior posts. I figured I would share it.

I have the 1st style fuel pump relay. I pulled the wire loom down a few inches and found where the clamp was holding the plastic shield, the wires had been rubbing together for the past 26 years and the insulation was gone. The power lead was touching the ECM ground.

Unfortunately I found this after throwing in the towel and beginning my transformation to a Q-jet and HEI for a CHUMP Series track car.

Hopefully this saves someone else.

 

Common problem, relay heats up, GMs terminal grease goes down the wire, expands the wire shielding and it slides down the wire. I clean the wire with carb cleaner then slide the wire covering back up an recrimp it to the connector.

 

Any pics?

 

https://www.thirdgen.org/forums/tbi/...y-harness.html
I think late 89 production was the first time replacing the flat connect fp relay to weatherpac. The fp current draw melts down the older style.

 

When I did my TPI conversion, I used a 87 wiring harness. All the wires to the relay pack had the insulation pulled back and the bare wires were exposed and touching. I installed a new connector with fresh wires. That was about 4 years ago. I plan to convert to the later style relays with the weatherpack connectors. I would suggest anyone with the older style relay pack, to check those wires once and a while.

 

This was the problem...

 

my wire's look similar but aren't touching, I've been meaning to track down new connectors and solder them in.

Interesting to find out what caused this. I always assumed a mouse with some free time decided to carefully nibble around the top of each wire for decoration.

 

The older style relays are crap, when too much amperage is drawn they do as pictured and the connectors loose tension. It's good to replace them with 89 up connectors and relays. Ac delco 15-8240
https://www.eficonnection.com/home/p...nector-pigtail

https://www.eficonnection.com/home/p...male-connector