No heat in 90 gmc 2500 van

I am having a problem with my van. I am getting basically no heat. This is not just heat inside the van. the heater core is fine, just repalced about a year ago, coolant flows through fine. What I have noticed though is that the whole system does not warm up. For example, yesterday I drove it for about 5 - 6 hours, and the radiator cap was only warm. It was NOT hot, I could basically hold my hand on it. I have replaced the termostat, and the rad cap.

Any other suggestions?

BTW- 4.3 L V6 engine.

Thanks

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heater core

Good heater performance is a function of the correct temperature range T-stat. Check the new stat and see what degree it is. It should be at least a 190 unit for good heat. Also make sure the new cap is the correct psi range too.

Hope this helps

Dave S(Texas)

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stuck radiaor fun cluch or stuck relay might be a nothe rreason. snipped-for-privacy@webtv.net wrote:

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