1989 GMC C1500 Flasher/Ignition issue

RYAN350CI

MEMBER
1989 GMC C1500
V8
2WD
MANUAL
286,000 MILES

When I turn the key to Ignition On position with my signal flasher installed, the ignition seems to "flash" untill the flasher is either removed or blows, but works fine without the flasher, minus having no signals. The hazard lights work for aprox. 5 seconds when the key is off then blows the fuse. I have checked all the wiring from the firewall forward and this all happens with the lights removed. The block in which the flasher is installed seems to be the culprit but I cannot seem to trace the fault. Can anyone tell me what that block is, what it does and possibly help me fix the issue?

3 Replies

KHLOW2008

MECHANIC
41,814 POSTS

Hi ryan350ci,

Thank you for the donation.

The block is known as the Convenient Center. It is for distributing the various circuits from the fuse box.

Symptoms indicates a wiring circuit shorting that is not going to be easy to resolve.

Did this problem occur after any repairs?
Did you check if any of the signal bulbs are blown or not working?

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Wednesday, June 9th, 2010 AT 11:47 AM

RYAN350CI

MEMBER
2 POSTS

All of the bulbs are new and work, I swapped the flasher and now it works, but the parking light fuse still pops as soon as I turn on the headlights, turn signals work fine, headlights and brakelights work, but the running lights do not. I pulled the dash and completely traced every wire in the truck, removed any unused circuits and the issue is still there. Is it possible to have an internal short in the convenient center block or the fuse block?

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Wednesday, June 9th, 2010 AT 12:33 PM

KHLOW2008

MECHANIC
41,814 POSTS

It is possible for the convenient center to have an internal short causing the problem.

Try removing the bulbs for the circuit and test if the fuse still blows. Uplug the convenient center wire for the running lights and test if shorting still occurs.

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Thursday, June 10th, 2010 AT 7:59 AM