another truck issue....

[0rion]

Truck is a 98 Blazer with the 4.3 in it. New battery and cables have been checked all the way to the starter. Battery shows good voltage until you turn the key and it bottoms out. Acts like a short but we can't find it. Only does it when the truck is hot.....after it sits overnight it starts just like it should but as soon as it heats up it starts acting like a short. I can't find the ignition relay....anyone know where that's at?

[Smittro]

It's been a few years since I messed with a 4.3 blazer iirc it's either in the fuse panel under the hood, or in the relay center in the glove box on some of them..iirc

[Smittro]

I pulled this from one of the blazer forums.

I believe this is the under hood one for the 98 blazer.

[Knight]

The solenoid or starter motor could also be faulty. I've had them do that exact same thing.

[Smittro]

The solenoid or starter motor could also be faulty. I've had them do that exact same thing.

I also agree with this. I've personally bench tested starters with bad solenoids that would pop the bench relays as well.

They would draw down the voltage guage to nearly zero and sometimes weld the solenoids internal contact plate in the closed circuit (start) position.

Usually though, if that happens on the engine the flywheel drags the starter armature because the starter drive stays engaged.

However getting back to the solenoid a field coil in the solenoid (there are 2) can short the system which would show as a heavy amper/volt draw on the guage as well as cook the starter relay.

In general though the starter relay is protected by a fuse.

[0rion]

this starter is about a year old....we changed that last year unrelated to the current issue........Once the truck has cooled down it fires right up. While it's hot though it acts just like a short to ground.